#include <bits/stdc++.h>
#define MAX 16000
using namespace std;
typedef array<int, 2> pr;
int A[MAX], B[MAX], val[MAX];
bool chk[MAX];
bitset<MAX> mask[MAX];
signed main() {
// ios_base::sync_with_stdio(false);
// cin.tie(0), cout.tie(0);
int N, M, S = 0, ans = -1, X;
pr K;
priority_queue<pr> pq;
vector<int> arr;
cin >> N;
for (int i = 1; i <= N; i++) {
cin >> A[i], S += A[i];
pq.push({A[i], i});
}
for (int i = 1; i <= S; i++)
for (int j = 1; j <= N; j++)
val[i] += min(i, A[j]);
cin >> M;
for (int i = 1; i <= M; i++)
cin >> B[i], chk[B[i]] = 1;
vector<vector<bitset<MAX>>> dp(S + 1);
dp[0] = vector<bitset<MAX>>(S + 1);
for (int i = 0; i <= S; i++)
dp[0][i][0] = 1;
for (int i = 1; i <= S; i++)
dp[i] = vector<bitset<MAX>>(S / i + 1);
mask[0][0] = 1;
for (int i = 1; i <= S; i++)
mask[i] = mask[i - 1], mask[i][i] = 1;
for (int i = 1; i <= S; i++) {
for (int j = S / i; j >= 1; j--) {
if (j < S / i)
dp[i][j] = dp[i][j + 1];
if (chk[j] && (i == 1 || j <= S / (i - 1)))
dp[i][j] |= dp[i - 1][j] << j;
dp[i][j] &= mask[val[i]];
}
}
for (int i = 1; i <= S; i++)
if (dp[i][1][S]) {
ans = i;
break;
}
cout << ans << '\n';
if (ans == -1)
return 0;
for (int i = ans; i >= 1; i--) {
for (int j = S / i; j >= 1; j--) {
if (!dp[i][j][S])
continue;
X = j, S -= j;
while (X--) {
K = pq.top(), pq.pop();
A[K[1]]--, arr.push_back(K[1]);
}
cout << arr.size() << ' ';
for (int i : arr)
cout << i << ' ', pq.push({A[i], i});
cout << '\n';
arr.clear();
break;
}
}
return 0;
}
