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].
import java.io.*;
    import java.math.BigInteger;
import java.text.DecimalFormat;
import java.util.*;
 
 
 
     
     
    public  class Main {
    	public static InputReader in;
        public static PrintWriter pw;
     
     
     
    	public static void main(String args[]) 
    	{
    		new Thread(null, new Runnable() {
                public void run() {
                    try{
                        solve();
                    }
                    catch(Exception e){
                        e.printStackTrace();
                    }
                }
            }, "1", 1 << 26).start();
        }
    	static ArrayList<Integer> g[];
    	static ArrayList<Integer> h[];
    	static boolean visited[];
    	static int[] parent;
    	static int par[];
    	static int degree[];
    	static int edjes=0;
    	static int start=-1;
    	static int end=-1;
    	static int Total=0;
    	static int time1[];
    	static int time2[];
    	static int glob=0;
    	static int[] ans;
    	static boolean vis2[][];
    	//static long sum1=0;
    	//static long val[];
        static ArrayList<Integer> levels[];
        static int max=0;
        static int lev=1;
        static ArrayList<Integer> nodes[];
        static ArrayList<Integer> values[];
        static int depth[];
        static boolean found=false;
       // static long sm[];
        static int sum1=0;
        static int pre[][];
        static int subtree[];
       static  int cnt=0;
       static  HashMap<String,Integer> hm;
       static int sm[];
       static int size[];
       static long mul[];
       static long d[]=new long[1000000];
       static int tot=0;
       static long highest=(long)1e9;
       static boolean bit=false;
        static Stack<Integer> tt=new Stack();
       static HashSet<Character> set;
 	   static long fact[],num[];
 	   static long MOD=1000000007;
 	   static int value[];static int premen[];
 	   static int count=0,index=0;
 	   static double ans11[];
 	   static int price[];
 	   static ArrayList<String> hp[][];
 	   static boolean visit[][];
 	   static int cnu[]=new int[1000001];
 	   static int label=1;
 	   static int his[][];
 	   static int size1=0;
 	   static int up[],down[];
 	   static int TotalUp=0;
 	   static long dist[];
 	//   static HashMap<String,Integer> hm1=new HashMap();
 	  // static HashMap<Integer,Integer> hm2=new HashMap();
 	   static TreeSet<Long> set1=new TreeSet();
 	  static  long DP[][][]=new long[20][200][1500];
 	 	static int t=-1,n=-1;
 	 	static int two[],min[],r[];
 	 	static int total[];static int black[];
 	 	static int Parent[];
 	 	static int subtree1[][];
 	 	static int tin[],tout[],a[];
 	 public static void solve() throws FileNotFoundException{
    		
    	
    		 in = new InputReader(System.in);
    		 pw = new PrintWriter(System.out);  
    	/*	 String p=in.readString();
    	     char c[]=p.toCharArray();
    	     int z[]=new int[p.length()];
    	     z[0]=0;
    	     int left=0;
    	     int right=0;
    	     for(int i=1;i<p.length();i++)
    	     {
    	    	 if(i>right)
    	    	 {
    	    		 
    	    		 left=right=i;
    	    		 while(right<p.length()&&c[right]==c[right-left])
    	    			 right++;
    	    		 z[i]=right-left;
    	    		 right--;
    	    	 }
    	    	 else
    	    	 {
    	    		 int k=i-left;
    	    		 if(z[k]<right-i+1)
    	    		 {
    	    			 z[i]=z[k];
    	    		 }
    	    		 else
    	    		 {
    	    			 left=i;
    	    			 while(right<p.length()&&c[right]==c[right-left])
        	    			 right++;
        	    		 z[i]=right-left;
        	    		 right--;
    	    		 }
    	    	 }
    	    	  
    	     }*/
    	        BigInteger x=new BigInteger(in.readString());
    	        BigInteger y=new BigInteger(in.readString());
    	        BigInteger l=new BigInteger(in.readString());
    	        BigInteger r=new BigInteger(in.readString());

    	        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 Par[]=new int[202];
 	 public static void Height(int cur,int par){
 		 Par[cur]=par;
 		 visited[cur]=true;
 		 int t=0;
 		 for(int x:g[cur])
 		 {
 			 if(!visited[x])
 			 { 
 				 t++;
 				 Height(x,cur);
 				 high[cur]=Math.max(high[cur], high[x]+1);
 			 }
 		 }
 		 if(t==0)
 		 {
 			 high[cur]=0;
 		 }
 	
 	 }
 	 static int dia[]=new int[202];
 	 static int high[]=new int[292];
 	 public static void Diameter(int curr,int parent)
 	 {
 		visited[curr]=true;
 		int trees=0;
 		ArrayList<Integer> set=new ArrayList();
 	
 		for(int x:g[curr])
 		{
 			if(!visited[x])
 			{
 				trees++;
 				Diameter(x,curr);
 				dia[curr]=Math.max(dia[curr],high[x]);
 				set.add(high[x]);
 			}
 		}
 		if(set.size()>=2)
 		{
 			Collections.sort(set,Collections.reverseOrder());
 			dia[curr]=Math.max(dia[curr],set.get(0)+set.get(1)+2);
 		}
 		else if(set.size()>0)
 		{
 			dia[curr]=Math.max(dia[curr],set.get(0)+1);
 		}
 		if(trees==0)
 		{
 			dia[curr]=0;
 		}

 	 }
 	 
      	 
 	 public static boolean IsPal(String s)
 	 {
 		 char c[]=s.toCharArray();
 		 for(int i=0;i<c.length/2;i++)
 		 {
 			 if(c[i]!=c[s.length()-1-i])
 				 return false;
 		 }
 		 return true;
 	 }
 	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 void dfs1(int curr,int parent)
 	  {
 		  visited[curr]=true;
 		  
 		  for(int x:g[curr])
 		  {
 			  
 			  if(x==parent)continue;
 			  depth[x]=depth[curr]+1;
 			  up[x]=up[curr];
 			  if(h[x].contains(curr)){
 				  up[x]++;
 				  TotalUp++;
 			  }
 			  dfs1(x,curr);
 		  }
 	  }
 	 
        
        
        public static void dfs(int curr,int Parent)
        {
        	visited[curr]=true;
        	size[curr]=1;
        	parent[curr]=Parent;
        	count++;
        	if(value[curr]>0)
        	{
        		index=value[curr];
        	}
        	for(int x:g[curr])
        	{
        		if(!visited[x])
        		{
        			dfs(x,curr);
        			size[curr]+=size[x];
        		}
        	}
        }
        static long ncr(long a, long b){
			if(b>a || b<0) return 0;
			long f = (fact[(int) a]*modInverse(((fact[(int) b]*fact[(int) (a-b)])%MOD), MOD))%MOD;
			return f;
		}
		static long modInverse(long a, long mOD2){
            return  power(a, mOD2-2, mOD2);
}
static long power(long x, long y, long m)
{
    if (y == 0)
        return 1;
    long p = power(x, y/2, m) % m;
    p = (p * p) % m;
 
    return (y%2 == 0)? p : (x * p) % m;
}
 
        public static long gcd(long x, long y) {
    		if (x == 0)
    			return y;
    		else
    			return gcd( y % x,x);
    	}	
        public static long power(long a,long b)
		{
			long result=1;
			while(b>0)
			{
				if(b%2==1)
					result*=a;
				a=a*a;
				b/=2;
			}
			return result;
		}
        static class Pair implements Comparable<Pair>{
        	int val;
        		//HashSet<Integer> s;
        		int index;
        		//int index;
        	//	int h;
        		Pair(int val,int index){
        	     	this.val=val;
        			this.index=index;
        		}
        		@Override
        		public int compareTo(Pair o) {
                          return val-o.val;
        		}
        				
        	}
    	static class InputReader {
     
    		private InputStream stream;
    		private byte[] buf = new byte[8192];
    		private int curChar, snumChars;
    		private SpaceCharFilter filter;
     
    		public InputReader(InputStream stream) {
    			this.stream = stream;
    		}
     
    		public int snext() {
    			if (snumChars == -1)
    				throw new InputMismatchException();
    			if (curChar >= snumChars) {
    				curChar = 0;
    				try {
    					snumChars = stream.read(buf);
    				} catch (IOException e) {
    					throw new InputMismatchException();
    				}
    				if (snumChars <= 0)
    					return -1;
    			}
    			return buf[curChar++];
    		}
     
    		public   int nextInt() {
    			int c = snext();
    			while (isSpaceChar(c))
    				c = snext();
    			int sgn = 1;
    			if (c == '-') {
    				sgn = -1;
    				c = snext();
    			}
    			int res = 0;
    			do {
    				if (c < '0' || c > '9')
    					throw new InputMismatchException();
    				res *= 10;
    				res += c - '0';
    				c = snext();
    			} while (!isSpaceChar(c));
    			return res * sgn;
    		}
     
    		public long nextLong() {
    			int c = snext();
    			while (isSpaceChar(c))
    				c = snext();
    			int sgn = 1;
    			if (c == '-') {
    				sgn = -1;
    				c = snext();
    			}
    			long res = 0;
    			do {
    				if (c < '0' || c > '9')
    					throw new InputMismatchException();
    				res *= 10;
    				res += c - '0';
    				c = snext();
    			} while (!isSpaceChar(c));
    			return res * sgn;
    		}
     
    		public int[] nextIntArray(int n) {
    			int a[] = new int[n];
    			for (int i = 0; i < n; i++)
    				a[i] = nextInt();
    			return a;
    		}
     
    		public String readString() {
    			int c = snext();
    			while (isSpaceChar(c))
    				c = snext();
    			StringBuilder res = new StringBuilder();
    			do {
    				res.appendCodePoint(c);
    				c = snext();
    			} while (!isSpaceChar(c));
    			return res.toString();
    		}
     
    		public boolean isSpaceChar(int c) {
    			if (filter != null)
    				return filter.isSpaceChar(c);
    			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    		}
     
    		public interface SpaceCharFilter {
    			public boolean isSpaceChar(int ch);
    		}
    	}
    }
 