Vasya has two arrays A and B of lengths n and m, respectively.

He can perform the following operation arbitrary number of times (possibly zero): he takes some consecutive subsegment of the array and replaces it with a single element, equal to the sum of all elements on this subsegment. For example, from the array [1, 10, 100, 1000, 10000] Vasya can obtain array [1, 1110, 10000], and from array [1, 2, 3] Vasya can obtain array [6].

Two arrays A and B are considered equal if and only if they have the same length and for each valid i A_i = B_i.

Vasya wants to perform some of these operations on array A, some on array B, in such a way that arrays A and B become equal. Moreover, the lengths of the resulting arrays should be maximal possible.

Help Vasya to determine the maximum length of the arrays that he can achieve or output that it is impossible to make arrays A and B equal.

Input

The first line contains a single integer n~(1 ≤ n ≤ 3 ⋅ 10^5) — the length of the first array.

The second line contains n integers a_1, a_2, ⋅⋅⋅, a_n~(1 ≤ a_i ≤ 10^9) — elements of the array A.

The third line contains a single integer m~(1 ≤ m ≤ 3 ⋅ 10^5) — the length of the second array.

The fourth line contains m integers b_1, b_2, ⋅⋅⋅, b_m~(1 ≤ b_i ≤ 10^9) - elements of the array B.

Output

Print a single integer — the maximum length of the resulting arrays after some operations were performed on arrays A and B in such a way that they became equal.

If there is no way to make array equal, print "-1".

Examples

Input

5
11 2 3 5 7
4
11 7 3 7


Output

3


Input

2
1 2
1
100


Output

-1


Input

3
1 2 3
3
1 2 3


Output

3
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
import java.util.Arrays;
import java.util.Random;
import java.io.FileWriter;
import java.io.PrintWriter;
/*
    Solution Created: 02:44:24 07/05/2021
    Custom Competitive programming helper.
*/
public class Main {
	public static void solve() {
		int n = in.nextInt();
		long[] a = in.nl(n);
		int m = in.nextInt();
		long[] b = in.nl(m);
		int l = 1, r = 1;
		long s1 = a[0], s2 = b[0];
		int ans = 1;
		while(l<n && r<m) {
			if(s1==s2) {
				ans++;
				if(l<n) s1 = a[l++];
				else s1 = 0;
				if(r<m) s2 = b[r++];
				else s2 = 0;
			}
			else if(s1>s2) {
				if(r==m) cant();
				s2 += b[r++];
			}else {
				if(l==n) cant();
				s1 += a[l++];
			}
		}
		while(l<n) s1 += a[l++];
		while(r<m) s2 += b[r++];
		if(s1!=s2) cant();
		out.println(ans);
	}
	public static void cant() {
		out.println(-1);
		out.exit();
		System.exit(0);
	}
	public static void main(String[] args) {
		in = new Reader();
		out = new Writer();
		int t = 1;
		while(t-->0) solve();
		out.exit();
	}
	static Reader in; static Writer out;

static class Reader {
	static BufferedReader br;
	static StringTokenizer st;
	
	public Reader() {
		this.br = new BufferedReader(new InputStreamReader(System.in));
	}
	
	public Reader(String f){
		try {
			this.br = new BufferedReader(new FileReader(f));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public int[] na(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++) a[i] = nextInt();
		return a;
	}

	public double[] nd(int n) {
		double[] a = new double[n];
		for (int i = 0; i < n; i++) a[i] = nextDouble();
		return a;
	}
	
	public long[] nl(int n) {
		long[] a = new long[n];
		for (int i = 0; i < n; i++) a[i] = nextLong();
		return a;
	}

	public char[] nca() {
		return next().toCharArray();
	}

	public String[] ns(int n) {
		String[] a = new String[n];
		for (int i = 0; i < n; i++) a[i] = next();
		return a;
	}

	public int nextInt() {
		ensureNext();
		return Integer.parseInt(st.nextToken());
	}

	public double nextDouble() {
		ensureNext();
		return Double.parseDouble(st.nextToken());
	}

	public Long nextLong() {
		ensureNext();
		return Long.parseLong(st.nextToken());
	}

	public String next() {
		ensureNext();
		return st.nextToken();
	}
	
	public String nextLine() {
		try {
			return br.readLine();
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
	
	private void ensureNext() {
		if (st == null || !st.hasMoreTokens()) {
			try {
				st = new StringTokenizer(br.readLine());
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

static class Util{
		private static Random random = new Random();
		static long[] fact;
		
		public static void initFactorial(int n, long mod) {
			fact = new long[n+1];
			fact[0] = 1;
			for (int i = 1; i < n+1; i++) fact[i] = (fact[i - 1] * i) % mod;
		}
		
		public static long modInverse(long a, long MOD) {
			long[] gcdE = gcdExtended(a, MOD);
			if (gcdE[0] != 1) return -1; // Inverted doesn't exist
			long x = gcdE[1];
			return (x % MOD + MOD) % MOD;
		}
		
		public static long[] gcdExtended(long p, long q) {
			if (q == 0) return new long[] { p, 1, 0 };
			long[] vals = gcdExtended(q, p % q);
			long tmp = vals[2];
			vals[2] = vals[1] - (p / q) * vals[2];
			vals[1] = tmp;
			return vals;
		}
		
		public static long nCr(int n, int r, long MOD) {
			if (r == 0) return 1;
			return (fact[n] * modInverse(fact[r], MOD) % MOD * modInverse(fact[n - r], MOD) % MOD) % MOD;
		}
		
		public static long nCr(int n, int r) {
			return (fact[n]/fact[r])/fact[n-r];
		}
		
		public static long nPr(int n, int r, long MOD) {
			if (r == 0) return 1;
			return (fact[n] * modInverse(fact[n - r], MOD) % MOD) % MOD;
		}
		public static long nPr(int n, int r) {
			return fact[n]/fact[n-r];
		}
		
		public static boolean isPrime(int n) { 
	        if (n <= 1) return false; 
	        if (n <= 3) return true; 
	        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; 
	    }
		
	    public static boolean[] getSieve(int n) {
	        boolean[] isPrime = new boolean[n+1];
	        for (int i = 2; i <= n; i++) isPrime[i] = true;
	        for (int i = 2; i*i <= n; i++) if (isPrime[i]) 
	                for (int j = i; i*j <= n; j++) isPrime[i*j] = false;
	        return isPrime;
	    }
	    
	    public static int gcd(int a, int b) { 
	    	int tmp = 0;
	    	while(b != 0) {
	    		tmp = b;
	    		b = a%b;
	    		a = tmp;
	    	}
	    	return a;
	    }
	    
	    public static long gcd(long a, long b) { 
	    	long tmp = 0;
	    	while(b != 0) {
	    		tmp = b;
	    		b = a%b;
	    		a = tmp;
	    	}
	    	return a;
	    }
	    
	    public static int random(int min, int max) {
	    	return random.nextInt(max-min+1)+min;
	    }
	    
		public static void dbg(Object... o) { 
			System.out.println(Arrays.deepToString(o)); 
		}
		
		public static void reverse(int[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				int tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static void reverse(int[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static void reverse(long[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				long tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static void reverse(long[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static void reverse(float[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				float tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static void reverse(float[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static void reverse(double[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				double tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static void reverse(double[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static void reverse(char[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				char tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static void reverse(char[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static <T> void reverse(T[] s, int l , int r) {
			for(int i = l; i<=(l+r)/2; i++) {
				T tmp = s[i];
				s[i] = s[r+l-i];
				s[r+l-i] = tmp;
			}
	    }
		
		public static <T> void reverse(T[] s) {
			reverse(s, 0, s.length-1);
	    }
		
		public static void shuffle(int[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            int t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
		
	    public static void shuffle(long[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            long t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
	    
	    public static void shuffle(float[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            float t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
	    
	    public static void shuffle(double[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            double t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
	    
	    public static void shuffle(char[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            char t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
	    
	    public static <T> void shuffle(T[] s) {
	        for (int i = 0; i < s.length; ++i) {
	            int j = random.nextInt(i + 1);
	            T t = s[i];
	            s[i] = s[j];
	            s[j] = t;
	        }
	    }
	    
		public static void sortArray(int[] a) {
	        shuffle(a);
	        Arrays.sort(a);
	    }
		
		public static void sortArray(long[] a) {
			shuffle(a);
	        Arrays.sort(a);
	    }
		
		public static void sortArray(float[] a) {
			shuffle(a);
	        Arrays.sort(a);
	    }
		
		public static void sortArray(double[] a) {
			shuffle(a);
	        Arrays.sort(a);
	    }
		
		public static void sortArray(char[] a) {
			shuffle(a);
	        Arrays.sort(a);
	    }
		
		public static <T extends Comparable<T>> void sortArray(T[] a) {
	        Arrays.sort(a);
	    }
	}

static class Writer {
	private PrintWriter pw;
	public Writer(){
		pw = new PrintWriter(System.out);
	}
	
	public Writer(String f){
		try {
			pw = new PrintWriter(new FileWriter(f));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public void printArray(int[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
	}
	
	public void printlnArray(int[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
		pw.println();
	}
	
	public void printArray(long[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
	}
	
	public void printlnArray(long[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
		pw.println();
	}
	
	public void print(Object o) {
		pw.print(o.toString());
	}
	
	public void println(Object o) {
		pw.println(o.toString());
	}
	
	public void println() {
		pw.println();
	}
	
	public void flush() {
		pw.flush();
	}
	public void exit() {
		pw.close();
	}
}
}
