#include<bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false); 

    int n;
    cin>>n;
    vector<int> a(n);
    for(int i = 0;i<n;i++) cin>>a[i];
    int m;
    cin>>m;
    vector<int> b(m);
    for(int i = 0;i<m;i++) cin>>b[i];
    vector<vector<char>> dp(1<<n,vector<char>(1<<m,0));
    dp[0][0] = 1;
    vector<int> sum(1<<n,0);
    for(int i = 0;i<1<<n;i++){
        for(int j = 0;j<n;j++) if(i>>j&1) sum[i] += a[j];
    }
    int mask = (1<<n) - 1;
    for(int i = 0;i<1<<n;i++){
        for(int j = 0;j<1<<m;j++){
            if(dp[i][j]==0) continue;
            int rest = mask ^ i;
            for(int k = rest;k>=0;k--){
                k &= rest;
                if(k==0) continue;
                for(int l = 0;l<m;l++){
                    if(j>>l&1) continue;
                    if(b[l]>=sum[k]) dp[i|k][j|(1<<l)] = 1;
                }
            }
        }
    }
    int ans = 1e9;
    for(int i = 0;i<1<<m;i++){
        if(dp[mask][i]) ans = min(ans,__builtin_popcount(i));
    }


    if(ans==1e9) ans = -1;
    cout<<ans<<endl;
}