import java.io.*;
import java.util.*;

public class SquareRoute2 {
	private static final Scanner cin = new Scanner(System.in);

	public static void main(String[] args) {
		while(true) {
			int n = cin.nextInt();
			int m = cin.nextInt();

			if(n == 0 && m == 0) { break; }

			int[] y = new int[n+1];
			int[] x = new int[m+1];

			for(int i = 1; i <= n; i++) {
				y[i] = y[i-1] + cin.nextInt();
			}

			for(int i = 1; i <= m; i++) {
				x[i] = x[i-1] + cin.nextInt();
			}

			Map<Integer,Integer> cx = new HashMap<Integer,Integer>();
			Map<Integer,Integer> cy = new HashMap<Integer,Integer>();

			for(int i = 0; i < y.length; i++) {
				for(int j = i + 1; j < y.length; j++) {
					int key = y[j] - y[i];
					int cur = cy.containsKey(key) ? cy.get(key) : 0;
					cy.put(key, cur + 1);
				}
			}

			for(int i = 0; i < x.length; i++) {
				for(int j = i + 1; j < x.length; j++) {
					int key = x[j] - x[i];
					int cur = cx.containsKey(key) ? cx.get(key) : 0;
					cx.put(key, cur + 1);
				}
			}

			int ans = 0;

			for(int key : cy.keySet()) {
				ans += cy.get(key) * (cx.containsKey(key) ? cx.get(key) : 0);
			}

			System.out.println(ans);
		}
	}
}