package no81;

import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static final int INF = 1 << 29;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		for(int i=0;i<n;i++) {
			a[i] = sc.nextInt();
		}
		int m = sc.nextInt();
		int[] b = new int[m];
		for(int i=0;i<m;i++) {
			b[i] = sc.nextInt();
		}
		int[][] dp = new int[m+1][1<<n]; //使用する箱の数の最小
		for(int i=0;i<=m;i++) {
			Arrays.fill(dp[i],INF);
		}
		dp[0][0] = 0;
		for(int i=0;i<m;i++) {
			for(int j=0;j<1<<n;j++) {
				if (dp[i][j] == INF) {
					continue;
				}
				dp[i+1][j] = Math.min(dp[i+1][j],dp[i][j]);
				for(int k=(j+1)|j;k<1<<n;k = (k + 1) | j) {
					int use = ~j & k;
					int sum = 0;
					for(int l=0;l<n;l++) {
						if ((use >> l & 1) > 0) {
							sum += a[l];
						}
					}
					if (sum <= b[i]) {
						dp[i+1][k] = Math.min(dp[i+1][k],dp[i][j]+1);
					}
				}
			}
		}
		int ans = dp[m][(1<<n)-1];
		System.out.println(ans == INF ? -1 : ans);
	}

}