#include<cstdio>
#include<limits>
#include<vector>
#define rep(i,a) for(int i=0;i<(a);++i)
#define repd(i,a) for(int i=(a);i>=0;--i)

const int MAX_N = 10, MAX_M = 10, INF = std::numeric_limits<int>::max()>>2;

int N, M;
int A[MAX_N], B[MAX_M];

int main()
{
	scanf( "%d", &N );
	rep( i, N )
		scanf( "%d", A+i );

	scanf( "%d", &M );
	rep( i, M )
		scanf( "%d", B+i );

	std::vector<int> cost( 1<<N );
	rep( i, 1<<N ) rep( k, N ) if( i>>k&1 )
		cost[i] += A[k];

	std::vector<int> dp( 1<<N, INF );
	dp[0] = 0;

	rep( i, M ) repd( j, (1<<N)-1 )
	{
		if( dp[j] == INF )
			continue;

		repd( k, (1<<N)-1 )
		{
			if( j&k || cost[k] > B[i] )
				continue;

			dp[j|k] = std::min( dp[j|k], dp[j]+1 );
		}
	}

	printf( "%d\n", dp[(1<<N)-1]==INF?-1:dp[(1<<N)-1] );

	return 0;
}