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

#define REP(i, n) for(ll i = 0; i < (ll)(n); i++)
#define FOR(i,n,m) for (ll i=n; i < (ll)(m); i++)
#define INF 1000000007
#define pb push_back

typedef long long ll;

int N,M;
int A[11],B[11];
int dp[11][2000];


int dfs(int m,int rest){
    if(rest==0) return 0;
    if(m==M) return dp[m][rest]=INF+1;
    if(dp[m][rest]!=INF) return dp[m][rest];
    REP(mask,1<<N){
        int inbox = rest & mask;
        if(inbox==0) continue;
        int sum_toy=0;
        REP(i,N){
            if(inbox>>i & 1) sum_toy+=A[i];
        }
        if(sum_toy<=B[m]) dp[m][rest]=min(dp[m][rest],1+dfs(m+1,rest-inbox));
        
    }
    if(dp[m][rest]!=INF) return dp[m][rest];
    return dp[m][rest]=INF+1;
}

int main(){
    cin >> N;
    REP(i,N){
        cin >> A[i];
    }
    cin >> M;
    REP(i,M){
        cin >> B[i];
    }
    sort(B,B+M,greater<int>());
    fill(dp[0],dp[11],INF);
    int ans = dfs(0,(1<<N)-1);
    if(ans<INF) cout << ans << endl;
    else cout << -1 << endl;
    return 0;
}