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

public class Main {
    static int[][] dp;
    static final int MOD = 1000000009;
    static ArrayList<ArrayList<Integer>> enables = new ArrayList<>();
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int[] toys = new int[n];
        for (int i = 0; i < n; i++) {
            toys[i] = sc.nextInt();
        }
        int[] weights = new int[1 << n];
        for (int i = 1; i < (1 << n); i++) {
            for (int j = 0; j < n; j++) {
                if ((i & (1 << j)) > 0) {
                    weights[i] += toys[j];
                }
            }
        }
        int m = sc.nextInt();
        for (int i = 0; i < m; i++) {
            int x = sc.nextInt();
            enables.add(new ArrayList<>());
            for (int j = 1; j < weights.length; j++) {
                if (weights[j] <= x) {
                    enables.get(i).add(j);
                }
            }
        }
        dp = new int[m][1 << n];
        for (int[] arr : dp) {
            Arrays.fill(arr, -1);
        }
        int ans = dfw(m - 1, (1 << n) - 1);
        if (ans >= Integer.MAX_VALUE / 2) {
            System.out.println(-1);
        } else {
            System.out.println(ans);
        }
    }
    
    static int dfw(int idx, int v) {
        if (v == 0) {
            return 0;
        }
        if (idx < 0) {
            return Integer.MAX_VALUE / 2;
        }
        if (dp[idx][v] < 0) {
            dp[idx][v] = dfw(idx - 1, v);
            for (int x : enables.get(idx)) {
                dp[idx][v] = Math.min(dp[idx][v], dfw(idx - 1, v ^ (v & x)) + 1);
            }
        }
        return dp[idx][v];
    }
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}