import java.util.*;

public class Main {
  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();
    }
    Arrays.sort(b);
    int[] sumb = new int[m + 1];
    for(int i = 1; i < m + 1; i++) {
      sumb[i] = sumb[i - 1] + b[m - i];
    }
    int p = (int)Math.pow(2, n);
    int[] dp = new int[p];
    int[] suma = new int[p];
    for(int i = 1; i < p; i++) {
      for(int j = 0; j < n; j++) {
        if((i & (1 << j)) != 0) suma[i] += a[j];
      }
    }

    for(int i = 0; i < p; i++) {
      dp[i] = 100;
    }

    dp[0] = 0;

    for(int i = 1; i < p; i++) {
      for(int j = 0; j < n; j++) {
        if((i & (1 << j)) != 0) {
          int i1 = i - (1 << j);
          if(dp[i1] >= 0) {
            int r = sumb[dp[i1]] - suma[i1];
            if(r >= a[j]) {
              dp[i] = Math.min(dp[i], dp[i1]);
            } else {
              if((dp[i1] < m) && (a[j] <= b[m - dp[i1] - 1]))  dp[i] = Math.min(dp[i], dp[i1] + 1);
            }
          } 
        }
      }
      if(dp[i] == 100) dp[i] = -1;
    }
    System.out.println(dp[p - 1]);
  }
}