#include <bits/stdc++.h>
    
using namespace std;
    
typedef long long ll;
const int  N = 5e2 + 12, MOD = (int)1e9 + 7;
 
int n, m, b[N], s = 0, val[N], c[N], p[N];
pair<int, int> a[N];
bool dp[N][N][N];
bool check(int j, int k) {
    return (val[k] >= j);
}
void out(int res) {
    vector<int> d;
    int i = m, j = s, k = res;
    while(j) {
        if(dp[i - 1][j][k]) {
            i--;
            continue;
        }
        assert(j - b[i] >= 0);
        j -= b[i];
        k--;
        d.push_back(b[i]);
        if(dp[i - 1][j][k]) {
            i--;
        }
    }
    cout << res << '\n';
    assert((int)d.size() == res);
    for(int i:d) {
        sort(a + 1, a + n + 1);
        reverse(a + 1, a + n + 1);
        cout << i << ' ';
        for(int j = 1; j <= i; j++) {
            a[j].first--;   
            cout << a[j].second << ' ';
        }
        cout << '\n';
    }
}
void test() {
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> a[i].first, c[i] = a[i].first;
        s += c[i];
        a[i].second = i;
    }
    sort(a + 1, a + n + 1);
    sort(c + 1, c + n + 1);
    for(int i = 1; i <= n; i++) {
        p[i] = p[i - 1] + c[i];
    }
    int it = n;
    for(int i = n; i >= 1; i--) {
        while(it >= 1 && c[it] >= i) {
            it--;
        }
        val[i] = p[it] + (n - it) * 1ll * i;
    }
    cin >> m;
    for(int i = 1; i <= m; i++) {
        cin >> b[i];
    }
    reverse(b + 1, b + m + 1);
    for(int i = 0; i <= m; ++i) {
        dp[i][0][0] = 1;
    }
    for(int i = 1; i <= m; i++) {
        for(int j = 1; j <= s; j++) {
            for(int k = 1; k <= s; k++) {
                dp[i][j][k] = dp[i - 1][j][k];
                if(j - b[i] >= 0 && (dp[i - 1][j - b[i]][k - 1] || dp[i][j - b[i]][k - 1]) && check(j, k)) {
                    dp[i][j][k] = 1;
                }
            }
        }
    }
    for(int i = 1; i <= s; i++) {
        if(dp[m][s][i]) {
            out(i);
            return;
        }
    }
    cout << -1 << '\n';
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); 
    
    int t = 1; 
    // cin >> t;
    
    while(t--) 
        test();
    return 0;
}