#include <bits/stdc++.h>
    
using namespace std;
    
typedef long long ll;
const int  N = 5e2 + 12, MOD = (int)1e9 + 7;

int n, a[N], b[N], m, dp[N], p[N];
const int inf = (int)1e9;
void test() {
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
        dp[i] = inf;
    }
    cin >> m;
    for(int i = 1; i <= m; i++) {
        cin >> b[i];
    }
    dp[0] = 0;
    for(int i = 1; i <= m; i++) {
        for(int j = b[i]; j <= n; j++) {
            if(dp[j - b[i]] + 1 < dp[j]) {
                p[j] = b[i];
                dp[j] = dp[j - b[i]] + 1;
            }
        }
    }
    if(dp[n] == inf) {
        cout << -1 << '\n';
        return;
    }
    vector<int> s;
    int x = n;
    while(x) {
        s.push_back(p[x]);
        x -= p[x];
    }
    cout << dp[n] << '\n';
    int it = 1;
    for(int i:s) {
        cout << i << ' ';
        for(int j = it; j < i + it; j++) {
            cout << j << ' ';
        }
        cout << '\n';
        it += i;
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); 
    
    int t = 1; 
    // cin >> t;
    
    while(t--) 
        test();
    return 0;
}