#include <cstdio>
#include <algorithm>

int N, M;
int A[10], B[10];
int cost[1<<10];

int dp[11][1<<10];

int main(){
    scanf("%d", &N);
    for(int i=0;i<N;i++){scanf("%d", A+i);}
    scanf("%d", &M);
    for(int i=0;i<M;i++){scanf("%d", B+i);}

    for(int i=0;i<(1<<N);i++){
        int c = 0;
        for(int j=0;j<N;j++){
            if(i >> j & 1){
                c += A[j];
            }
        }

        cost[i] = c;
    }

    std::fill(&dp[0][0], &dp[0][0]+11*(1<<10), 100);
    dp[0][0] = 0;
    for(int i=0;i<M;i++){
        for(int j=0;j<(1<<N);j++){
            dp[i+1][j] = std::min(dp[i+1][j], dp[i][j]);
            for(int k=0;k<(1<<N);k++){
                if(j & k){continue;}
                if(cost[k] > B[i]){continue;}
                dp[i+1][j|k] = std::min(dp[i+1][j|k], dp[i][j] + 1);
            }
        }
    }
    
    if(dp[M][(1<<N)-1] < 100){
        printf("%d\n", dp[M][(1<<N)-1]);
    }else{
        puts("-1");
    }
}