#pragma GCC optimize("unroll-loops,O3")
#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) void(23)
#endif
template<typename T>
bool chmin(T& a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
constexpr int max_N = 500 + 5;
int N;
int A[max_N];
int M;
int B[max_N];
int dp[max_N][max_N][max_N];
int sums[max_N];
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::cin >> N;
for (int i = 0; i < N; ++i) {
std::cin >> A[i];
}
std::cin >> M;
for (int i = 0; i < M; ++i) {
std::cin >> B[i];
}
std::reverse(B, B + M);
for (int i = 0; i < max_N; ++i) {
for (int j = 0; j < N; ++j) {
sums[i] += std::min(A[j], i + 1);
}
}
dp[0][0][0] = true;
for (int i = 0; i < max_N; ++i) {
for (int j = 0; j < M; ++j) {
for (int k = 0; k < max_N; ++k) {
if (!dp[i][j][k]) {
continue;
}
dp[i][j + 1][k] = true;
if (k + B[j] <= sums[i]) {
dp[i + 1][j][k + B[j]] = true;
}
}
}
}
int all = std::accumulate(A, A + N, 0);
int cnt = 0;
while (cnt != max_N && !dp[cnt][M][all]) {
cnt += 1;
}
if (cnt == max_N) {
std::cout << "-1\n";
return 0;
}
std::vector<int> taken;
int b = M, c = all;
for (int a = cnt; a >= 1; --a) {
while (b >= 0 && dp[a][b - 1][c]) {
b -= 1;
}
assert(b != M && dp[a - 1][b][c - B[b]]);
taken.emplace_back(B[b]);
c -= B[b];
}
std::vector<std::vector<int>> ans;
for (auto i : taken) {
std::vector<int> p(N);
std::iota(p.begin(), p.end(), 0);
std::sort(p.begin(), p.end(), [&](auto lhs, auto rhs) {
return A[lhs] > A[rhs];
});
ans.emplace_back();
for (int j = 0; j < i; ++j) {
A[p[j]] -= 1;
ans.back().emplace_back(p[j]);
}
}
std::cout << ans.size() << '\n';
for (auto v : ans) {
std::cout << v.size();
for (auto i : v) {
std::cout << ' ' << i + 1;
}
std::cout << '\n';
}
return 0;
}
