#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 1e5 + 5, INF = 1e9;
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
int n, m;
cin >> n;
pair<int,int> a[n+1];
for (int i=1;i<=n;i++) {cin >> a[i].first, a[i].second = i;}
cin >> m;
int b[m];
for (int i=0;i<m;i++) cin >> b[i];
sort(a+1, a+n+1);
int mx = a[n].first;
int freq[mx+2];
for (int i=0;i<=mx+1;i++) freq[i] = 0;
for (int i=1;i<=n;i++) freq[a[i].first]++;
for (int i=mx;i>=1;i--) freq[i] += freq[i+1];
vector<pair<int,int>> vec = {{0, 0}};
for (int i=mx;i>=1;i--) {
for (int j=1;j<=freq[i];j++) vec.push_back({a[n - freq[i] + j].second, min(freq[i+1]+j, freq[i])});
}
int sz = vec.size();
// for (auto [x, y]:vec) cout << x << "." << y << " "; cout << endl;
pair<int,int> dp[sz];
for (int i=0;i<sz;i++) dp[i] = {INF, -1};
dp[0] = {0, -1};
for (int i=1;i<sz;i++) {
for (int j:b) if (i - j >= 0 && j <= vec[i].second) {
dp[i] = min(make_pair(dp[i-j].first+1, i - j), dp[i]);
}
// cout << i << " " << vec[i].second << " " << dp[i].first << " " << dp[i].second << endl;
}
// return 0;
if (dp[sz-1].first == INF) cout << "-1\n";
else {
cout << dp[sz-1].first << "\n";
int u = sz-1;
while (u != 0) {
int v = dp[u].second;
cout << u - v << " ";
while (u > v) {
cout << vec[u].first << " ";
u--;
}
cout << "\n";
u = v;
}
}
}
