#include <bits/stdc++.h>
using namespace std;
int main() {
int n, tot = 0;
cin >> n;
priority_queue<pair<int,int>> pq;
for(int i=0,a;i<n;i++) {
cin >> a;
tot += a;
pq.push({a,i});
}
vector<vector<int>> sol;
auto add = [&pq,&sol](int s) {
sol.push_back(vector<int>(s,0));
vector<pair<int,int>> used;
for(int i=0;i<s;i++) {
auto [cnt, idx] = pq.top();
assert(cnt);
pq.pop();
used.push_back({cnt-1,idx});
sol.back()[i] = idx;
}
for(auto i: used)
pq.push(i);
};
int m;
cin >> m;
int b[m];
for(int i=0;i<m;i++)
cin >> b[i];
int dp[m][b[0]];
memset(dp,1,sizeof(dp));
dp[0][0] = 0;
for(int i=1;i<m;i++) {
memcpy(dp[i],dp[i-1],sizeof(dp[i]));
for(int j=0;j<b[0];j++)
dp[i+1][(j+b[i])%b[0]] = min(dp[i+1][(j+b[i])%b[0]],dp[i+1][j]+b[i]-b[0]);
for(int j=0;j<b[0];j++)
dp[i+1][(j+b[i])%b[0]] = min(dp[i+1][(j+b[i])%b[0]],dp[i+1][j]+b[i]-b[0]);
}
if(dp[m-1][tot%b[0]] > tot - 1LL * b[0] * pq.top().first) {
cout << -1;
return 0;
}
int i0 = m-1, j0 = tot % b[0];
while(i0) {
if(dp[i0][j0] == dp[i0][((j0-b[i0])%b[0]+b[0])%b[0]] + b[i0] - b[0]) {
add(b[i0]);
j0 = ((j0 - b[i0]) % b[0] + b[0]) % b[0];
tot -= b[i0];
} else
i0--;
}
for(int i=0;i<tot/b[0];i++)
add(b[0]);
cout << sol.size() << "\n";
for(auto i: sol) {
cout << i.size() << " ";
for(auto j: i)
cout << j+1 << " ";
cout << "\n";
}
}
