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

typedef long long ll;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef pair< int, int > pii;
typedef vector< pii > vp;
typedef vector< double > vd;
typedef vector< vd > vvd;
typedef vector< string > vs;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

const int INF = 0x3f3f3f3f;

int N;
vi A;
int M;
vi B;

void init(){
  cin >> N;
  A = vi( N );
  for( int i = 0; i < N; ++i )
    cin >> A[ i ];
  cin >> M;
  B = vi( M );
  for( int i = 0; i < M; ++i )
    cin >> B[ i ];
}

int ans = INF;

void preprocess(){
  sort( B.begin(), B.end(), greater< int >() );
  sort( A.begin(), A.end() );
  do{
    int ptr_a = 0;
    for( int i = 0; i < M; ++i ){
      int s = B[ i ];
      while( ptr_a < N and s >= A[ ptr_a ] )
        s -= A[ ptr_a++ ];
      if( ptr_a == N ){
        upmin( ans, i + 1 );
        break;
      }
    }
  } while( next_permutation( A.begin(), A.end() ) );
}

void solve(){
  if( ans == INF )
    cout << -1 << endl;
  else
    cout << ans << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}