#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
const int maxn = 15005;

bitset<maxn> dp[300005];
priority_queue<pii> pq;
vector<int> v, res[maxn];
int a[maxn], b[maxn], id[maxn], pre[300005], tmp[maxn], sum[maxn], c[maxn], cnt;
bool cmp(int x, int y) { return a[x] < a[y]; }
bool cmp2(int x, int y) { return x > y; }

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	
	int n, m, S = 0;
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i], S += a[i], id[i] = i;
	sort(id + 1, id + n + 1, cmp);
	int lst = 0, nw = 0;
	for (int i = 1; i <= n; i++)
	{
		for (int j = lst + 1; j <= a[id[i]]; j++) sum[j] = nw + (n - i + 1) * j;
		nw += a[id[i]];
		lst = a[id[i]];
	}
	for (int j = lst + 1; j <= S; j++) sum[j] = nw;
	
	cin >> m;
	for (int i = 1; i <= m; i++) cin >> b[i];
	
	dp[++cnt][S] = 1;
	tmp[0] = 1;
	for (int i = m; i; i--)
	{
		v.clear();
		for (int j = 0; j <= S / b[i]; j++)
		{
			cnt++;
			v.emplace_back(cnt);
			pre[cnt] = tmp[j];
			if (tmp[j]) dp[cnt] = dp[tmp[j]];
			tmp[j] = cnt;
		}
		for (int j = 0; j < S / b[i]; j++) dp[v[j + 1]] |= (dp[v[j]] >> b[i]);
		for (int j = 0; j <= S / b[i]; j++) dp[v[j]] = (dp[v[j]] >> (S - sum[j])) << (S - sum[j]);
	}
	
	int ans = -1, pos;
	for (int i = 0; i < v.size(); i++)
		if (dp[v[i]][0])
		{
			ans = i;
			pos = v[i];
			break; 
		}
	if (ans == -1)
	{
		cout << "-1";
		return 0;
	}
	
	cout << ans << "\n";
	int x = pos, y = 0, ddd = ans;
	for (int i = 1; i <= m; i++)
	{
		if (!x) break;
		while (x && dp[x - 1][y + b[i]])
		{
			c[ddd--] = b[i];
			x--;
			y += b[i];
		}
		x = pre[x];
	}
	
	for (int i = 1; i <= ans; i++) pq.push(make_pair(c[i], i));
	for (int i = 1; i <= n; i++)
	{
		v.clear();
		for (int j = 1; j <= a[id[i]]; j++)
			v.emplace_back(pq.top().second), pq.pop();
		for (int j = 0; j < a[id[i]]; j++)
			res[v[j]].emplace_back(id[i]), c[v[j]]--, pq.push(make_pair(c[v[j]], v[j]));
	}
	
	for (int i = 1; i <= ans; i++)
	{
		cout << res[i].size() << " ";
		for (int x : res[i]) cout << x << " ";
		cout << "\n";
	}
	return 0;
}