Unlucky year in Berland is such a year that its number n can be represented as n = xa + yb, where a and b are non-negative integer numbers. 

For example, if x = 2 and y = 3 then the years 4 and 17 are unlucky (4 = 20 + 31, 17 = 23 + 32 = 24 + 30) and year 18 isn't unlucky as there is no such representation for it.

Such interval of years that there are no unlucky years in it is called The Golden Age.

You should write a program which will find maximum length of The Golden Age which starts no earlier than the year l and ends no later than the year r. If all years in the interval [l, r] are unlucky then the answer is 0.

Input

The first line contains four integer numbers x, y, l and r (2 ≤ x, y ≤ 1018, 1 ≤ l ≤ r ≤ 1018).

Output

Print the maximum length of The Golden Age within the interval [l, r].

If all years in the interval [l, r] are unlucky then print 0.

Examples

Input

2 3 1 10


Output

1


Input

3 5 10 22


Output

8


Input

2 3 3 5


Output

0

Note

In the first example the unlucky years are 2, 3, 4, 5, 7, 9 and 10. So maximum length of The Golden Age is achived in the intervals [1, 1], [6, 6] and [8, 8].

In the second example the longest Golden Age is the interval [15, 22].
	        			/*
	        		     * Author- Priyam Vora
	        		     * BTech 2nd Year DAIICT
	        		     */
	     
	     
	        		    import java.awt.Checkbox;
	import java.awt.Point;
	import java.io.*;
	        		    import java.math.*;
	        		    import java.util.*;
	import java.util.Map.Entry;
	
	import javax.print.attribute.SetOfIntegerSyntax;
	
	     
	        		    public class Main{
	        		  	private static InputStream stream;
	        		    	private static byte[] buf = new byte[1024];
	        		    	private static int curChar;
	        		    	private static int numChars;
	        		    	private static SpaceCharFilter filter;
	        		    	private static PrintWriter pw;
	        		    	private static long count = 0,mod=1000000007;
	        		    //	private static TreeSet<Integer> ts=new TreeSet[200000];
	        		    	public final static int INF = (int) 1E9;
	
	        		        
	        		        public static void main(String[] args) {
	        		        	InputReader(System.in);
	        		    		pw = new PrintWriter(System.out); 
	        		            new Thread(null ,new Runnable(){
	        		               public void run(){
	        		                   try{
	        		                       solve();
	        		                       pw.close();
	        		                   } catch(Exception e){
	        		                       e.printStackTrace();
	        		                   }
	        		               }
	        		           },"1",1<<26).start();
	        		       }
	        		        public static long pow(long n, long p,long mod) {
	        					if(p==0)
	        						return 1;
	        					if(p==1)
	        						return n%mod;
	        					if(p%2==0){
	        						long temp=pow(n, p/2,mod);
	        					return (temp*temp)%mod;
	        					}else{
	        						 	long temp=pow(n,p/2,mod);
	        						 	temp=(temp*temp)%mod;
	        						 	return(temp*n)%mod;
	        						 	
	        					}
	        				}
	        		        public static long pow(long n, long p) {
	        					if(p==0)
	        						return 1;
	        					if(p==1)
	        						return n;
	        					if(p%2==0){
	        						long temp=pow(n, p/2);
	        					return (temp*temp);
	        					}else{
	        						 	long temp=pow(n,p/2);
	        						 	temp=(temp*temp);
	        						 	return(temp*n);
	        						 	
	        					}
	        				}
	        		        public static void Merge(long a[],int p,int r){
	        		            if(p<r){
	        		                int q = (p+r)/2;
	        		                Merge(a,p,q);
	        		                Merge(a,q+1,r);
	        		                Merge_Array(a,p,q,r);
	        		            }
	        		        }
	        		        public static void Merge_Array(long a[],int p,int q,int r){
	        		           long b[] = new long[q-p+1];
	        		            long c[] = new long[r-q];
	        		            for(int i=0;i<b.length;i++)
	        		                b[i] = a[p+i];
	        		            for(int i=0;i<c.length;i++)
	        		                c[i] = a[q+i+1];
	        		            int i = 0,j = 0;
	        		            for(int k=p;k<=r;k++){
	        		                if(i==b.length){
	        		                    a[k] = c[j];
	        		                    j++;
	        		                }
	        		                else if(j==c.length){
	        		                    a[k] = b[i];
	        		                    i++;
	        		                }
	        		                else if(b[i]<c[j]){
	        		                    a[k] = b[i];
	        		                    i++;
	        		                }
	        		                else{
	        		                    a[k] = c[j];
	        		                    j++;
	        		                }
	        		            }
	        		        }
	        		    	public static long gcd(long x, long y) {
	        		    		if (x == 0)
	        		    			return y;
	        		    		else
	        		    			return gcd( y % x,x);
	        		    	}	public static boolean isPrime(int n) {
	        		    	// Corner cases
				    		if (n <= 1)
				    			return false;
				    		if (n <= 3)
				    			return true;
				     
				    		// This is checked so that we can skip 
				    		// middle five numbers in below loop
				    		if (n % 2 == 0 || n % 3 == 0)
				    			return false;
				     
				    		for (int i = 5; i * i <= n; i = i + 6)
				    			if (n % i == 0 || n % (i + 2) == 0)
				    				return false;
				     
				    		return true;
				    	}
	        		        static LinkedList<Integer> adj[];
	        		        static boolean Visited[];
	        		        static HashSet<Integer> exc;
	        		        static long oddsum[]=new long[1000001];
	        		        static int co=0,ans=0;
	        		       
	        		        static int n,m;
	        		        static String s[];
	        		        static int ind;
	        		        public static void solve() {
	        		  
	        		        	String s=nextLine();
	        		        	String c[]=s.split(" ");
	        		        	 BigInteger x=new BigInteger(c[0]);
	        		    	        BigInteger y=new BigInteger(c[1]);
	        		    	        BigInteger l=new BigInteger(c[2]);
	        		    	        BigInteger r=new BigInteger(c[3]);

	        		    	        ArrayList<BigInteger> list=new ArrayList<>();
	        		    	        
	        		    	        for(int a=0;a<=64;a++){
	        		    	            for(int b=0;b<=64;b++){
	        		    	                BigInteger tmp=x.pow(a).add(y.pow(b));
	        		    	                if(tmp.compareTo(l)>=0 && r.compareTo(tmp)>=0){
	        		    	                    list.add(tmp);
	        		    	                }
	        		    	            }
	        		    	        }
	        		    	        list.add(l.subtract(BigInteger.ONE));
	        		    	        list.add(r.add(BigInteger.ONE));
	        		    	        Collections.sort(list);
	        		    	        long ans=0;
	        		    	        
	        		    	        for(int i=1;i<list.size();i++){
	        		    	            BigInteger b=list.get(i).subtract(list.get(i-1));
	        		    	            long tmp=b.longValue()-1;
	        		    	            ans=Math.max(ans,tmp);
	        		    	        }

	        		    	       System.out.println(ans);
	        		        }
	        		        
	        		        static int[] levl;
	        		        static int h_max=0;
	        		     public static void dfs(int curr,int lev){
	        		    	 Visited[curr]=true;
	        		    	 levl[curr]=lev;
	        		    	 h_max=Math.max(h_max, levl[curr]);
	        		    	 for(int x:adj[curr]){
	        		    		 if(!Visited[x]){
	        		    			 dfs(x,lev+1);
	        		    		 }
	        		    	 }
	        		     }
	        		       
	        		        public static String reverseString(String s) {
	        					StringBuilder sb = new StringBuilder(s);
	        					sb.reverse();
	        					return (sb.toString());
	        				}
	        		        
	        		        
	        		        private static void BFS(int sou,int dest){
	        		        	Queue<Integer> q=new LinkedList<Integer>();
	        		        	q.add(sou);
	        		        	Visited[sou]=true;
	        		        	while(!q.isEmpty()){
	        		        		int top=q.poll();
	        		        		
	        		        		for(int i:adj[top]){
	        		        			//pw.println(i+" "+top);
	        		        			if(!Visited[i])
	        		        			{
	        		        				
	        		        				q.add(i);
	        		        			}
	        		        			
	        		        			Visited[i]=true;
	        		        			if(i==dest){
	        		        				pw.println("Yes");
	        		        			return;	
	        		        			}
	        		        		}
	        		        	}
	        		        	pw.println("No");
	        		        	
	        		        	
	        		        }
	        		        
	        		        private static long ncr(int n,int k){
	    				    	if (k < 0 || k > n) return 0;
	    				        if (n-k < k) k = n-k;
	    			
	    				        BigInteger x = BigInteger.ONE;
	    				        for (int i = 1; i <= k; i++) {
	    				            x = x.multiply(new BigInteger(""+(n-i+1)));
	    				            x = x.divide(new BigInteger(""+i));
	    				        }
	    			
	    				return x.longValue();
	    				    }
	        		       private  static long fact(long count){
	        		        	long ans=1;
	        		        	for(int i=1;i<=count;i++){
	        		        		ans*=i;
	        		        	}
	        		        	return ans;
	        		        }
	        		        
	        		        
	        		        static int state=1;
	        		        static long no_exc=0,no_vert=0;
	        		      static Stack<Integer> st;
	        		      static HashSet<Integer> inset;
	        		        private static void topo(int curr){
	        		        	
	        		        	Visited[curr]=true;
	        		        	inset.add(curr);
	        		        	for(int x:adj[curr]){
	        		        		if(adj[x].contains(curr) || inset.contains(x)){
	        		        			state=0;
	        		        			return;
	        		        		}
	        		        		if(state==0)
	        		        			return;
	        		        		
	        		        	}
	        		        	st.push(curr);
	        		        	
	        		        	inset.remove(curr);
	        		        }
	        		        static HashSet<Integer> hs;
	        		       
	        		     	private static void buildgraph(int n){
	        		    		adj=new LinkedList[n+1];
	        		    		Visited=new boolean[n+1];
	        		    		
	        		    		for(int i=0;i<=n;i++){
	        		    			adj[i]=new LinkedList<Integer>();
	        		    		
	        		    		}
	     
	     
	        		    	}
	        		     	
	        		    	// To Get Input
	        		    	// Some Buffer Methods
	     
	        		     	public static void sort(long a[]){
	        		     		Merge(a, 0, a.length-1);
	        		     	}
	        		    	public static void InputReader(InputStream stream1) {
	        		    		stream = stream1;
	        		    	}
	     
	        		    	private static boolean isWhitespace(int c) {
	        		    		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	        		    	}
	     
	        		    	private static boolean isEndOfLine(int c) {
	        		    		return c == '\n' || c == '\r' || c == -1;
	        		    	}
	     
	        		    	private static int read() {
	        		    		if (numChars == -1)
	        		    			throw new InputMismatchException();
	        		    		if (curChar >= numChars) {
	        		    			curChar = 0;
	        		    			try {
	        		    				numChars = stream.read(buf);
	        		    			} catch (IOException e) {
	        		    				throw new InputMismatchException();
	        		    			}
	        		    			if (numChars <= 0)
	        		    				return -1;
	        		    		}
	        		    		return buf[curChar++];
	        		    	}
	     
	        		    	private static int nextInt() {
	        		    		int c = read();
	        		    		while (isSpaceChar(c))
	        		    			c = read();
	        		    		int sgn = 1;
	        		    		if (c == '-') {
	        		    			sgn = -1;
	        		    			c = read();
	        		    		}
	        		    		int res = 0;
	        		    		do {
	        		    			if (c < '0' || c > '9')
	        		    				throw new InputMismatchException();
	        		    			res *= 10;
	        		    			res += c - '0';
	        		    			c = read();
	        		    		} while (!isSpaceChar(c));
	        		    		return res * sgn;
	        		    	}
	     
	        		    	private static long nextLong() {
	        		    		int c = read();
	        		    		while (isSpaceChar(c))
	        		    			c = read();
	        		    		int sgn = 1;
	        		    		if (c == '-') {
	        		    			sgn = -1;
	        		    			c = read();
	        		    		}
	        		    		long res = 0;
	        		    		do {
	        		    			if (c < '0' || c > '9')
	        		    				throw new InputMismatchException();
	        		    			res *= 10;
	        		    			res += c - '0';
	        		    			c = read();
	        		    		} while (!isSpaceChar(c));
	        		    		return res * sgn;
	        		    	}
	     
	        		    	private static String nextToken() {
	        		    		int c = read();
	        		    		while (isSpaceChar(c))
	        		    			c = read();
	        		    		StringBuilder res = new StringBuilder();
	        		    		do {
	        		    			res.appendCodePoint(c);
	        		    			c = read();
	        		    		} while (!isSpaceChar(c));
	        		    		return res.toString();
	        		    	}
	     
	        		    	private static String nextLine() {
	        		    		int c = read();
	        		    		while (isSpaceChar(c))
	        		    			c = read();
	        		    		StringBuilder res = new StringBuilder();
	        		    		do {
	        		    			res.appendCodePoint(c);
	        		    			c = read();
	        		    		} while (!isEndOfLine(c));
	        		    		return res.toString();
	        		    	}
	     
	        		    	private static int[] nextIntArray(int n) {
	        		    		int[] arr = new int[n];
	        		    		for (int i = 0; i < n; i++) {
	        		    			arr[i] = nextInt();
	        		    		}
	        		    		return arr;
	        		    	}
	     
	        		    	private static long[][] next2dArray(int n, int m) {
	        		    		long[][] arr = new long[n][m];
	        		    		for (int i = 0; i < n; i++) {
	        		    			for (int j = 0; j < m; j++) {
	        		    				arr[i][j] = nextLong();
	        		    			}
	        		    		}
	        		    		return arr;
	        		    	}
	        		    	private static char[][] nextCharArray(int n,int m){
	        		    		char [][]c=new char[n][m];
	        		    		for(int i=0;i<n;i++){
	        		    			String s=nextLine();
	        		    			for(int j=0;j<s.length();j++){
	        		    				c[i][j]=s.charAt(j);
	        		    			}
	        		    		}
	        		    		return c;
	        		    	}
	     
	        		    	private static long[] nextLongArray(int n) {
	        		    		long[] arr = new long[n];
	        		    		for (int i = 0; i < n; i++) {
	        		    			arr[i] = nextLong();
	        		    		}
	        		    		return arr;
	        		    	}
	     
	        		    	private static void pArray(int[] arr) {
	        		    		for (int i = 0; i < arr.length; i++) {
	        		    			pw.print(arr[i] + " ");
	        		    		}
	        		    		pw.println();
	        		    		return;
	        		    	}
	     
	        		    	private static void pArray(long[] arr) {
	        		    		for (int i = 0; i < arr.length; i++) {
	        		    			pw.print(arr[i] + " ");
	        		    		}
	        		    		pw.println();
	        		    		return;
	        		    	}
	     
	        		    	private static void pArray(boolean[] arr) {
	        		    		for (int i = 0; i < arr.length; i++) {
	        		    			pw.print(arr[i] + " ");
	        		    		}
	        		    		pw.println();
	        		    		return;
	        		    	}
	     
	        		    	private static boolean isSpaceChar(int c) {
	        		    		if (filter != null)
	        		    			return filter.isSpaceChar(c);
	        		    		return isWhitespace(c);
	        		    	}
	     
	        		    	private interface SpaceCharFilter {
	        		    		public boolean isSpaceChar(int ch);
	        		    	}
	     
	     
	    }
	        		    
	        		           		    class Node{
	        		    	int to;
	        		    	long dist;
	        		    	Node(int to,long dist){
	        		    		this.to=to;
	        		    		this.dist=dist;
	        		    	}
	        		    	
	        		    }
	        		    class Pair implements Comparable<Pair>{
	        				
	    					
	    					int x,y;
	    					Pair(int x,int y){
	    					
	    						this.x=x;
	    						this.y=y;
	    					
	    					}
	    					@Override
	    					public int compareTo(Pair o) {
	    				
	    					/*	if(((double)a/(double)b)!=((double)o.a/(double)o.b))
	    						return (int)(((double)o.a/(double)o.b)-((double)a/(double)b));
	    						else*/
	    							
	    						//return (int)(o.size-size);
	    						if((x+y)==(o.x+o.y))
	    							return x-o.x;
	    						return (x+y)-(o.x+o.y);
	    					}
	    					public int hashCode() {
	    							//int hu = (int) (x ^ (x >>> 32));
	    							//int hv = (int) (y ^ (y >>> 32));
	    							//int hw = (int) (mass ^ (mass >>> 32));
	    							//return 31 * hu + hv ;
	    						return 0;
	    						}
	    						public boolean equals(Object o) {
	    							Pair other = (Pair) o;
	    						//	return x == other.x && y == other.y;
	    						return false;
	    						}
	    				}  class Dsu{
		    		    	private int rank[], parent[] ,n;
		    		    	private static int[] parent1;
		    		    	Dsu(int size){
		    		    		this.n=size+1;
		    		    		rank=new int[n];
		    		    		//parent=new int[n];
		    		    		parent=new int[n];
		    		    	makeSet();
		    		
		    		    	}
		    		    	
		    		    	void makeSet(){
		    		    		for(int i=0;i<n;i++){
		    		    			parent[i]=i;
		    		    		}
		    		    	}
		    		    	
		    		    	int find(int x){
		    		    		if(parent[x]!=x){
		    		    			
		    		    			parent[x]=find(parent[x]);
		    		    		}
		    		    		return parent[x];
		    		    	}
		    		    
		    		    	
		    		    	boolean union(int x,int y){
		    		    		int xRoot=find(x);
		    		    		int yRoot=find(y);
		    		    		
		    		    		if(xRoot==yRoot)
		    		    			return false;
		    		    		if(rank[xRoot]<rank[yRoot]){
		    		    		parent[xRoot]=yRoot;	
		    		    		}else if(rank[yRoot]<rank[xRoot]){
		    		    			parent[yRoot]=xRoot;
		    		    		}else{
		    		    			parent[yRoot]=xRoot;
		    		    			rank[xRoot]++;
		    		    		}
		    		    		return true;
		    		    	}
	
		    		     
		    		    }