#include<bits/stdc++.h>
# define int long long
# define rep(i, j, k) for (int i = j; i <= k; ++i)
# define id(i, j) (plc[i] + (j))
using namespace std;

bitset < 15005 > ok[300005];
int n, a[15005], st[15005], pre[15005], sum, m, b[15005], can[15005];
int plc[15005], len[15005];
int stk[15005], r;
int now[15005], pos[15005];
bool cmp(int x, int y){return a[x] > a[y];}
signed main()
{
	//freopen("ex_3.in", "r", stdin);
//	freopen("c.out", "w", stdout);
	ios::sync_with_stdio(false); cin.tie(0), cout.tie(0);
	cin >> n;
	rep(i, 1, n) cin >> a[i], st[i] = i;
	sort(st + 1, st + n + 1, cmp);
    rep(i, 1, n) pre[i] = pre[i - 1] + a[st[i]], sum += a[i];
	cin >> m;
	rep(i, 1, m) cin >> b[i], can[b[i]] = 1;
	rep(i, 2, sum + 1) plc[i] = plc[i - 1] + (len[i - 1] = sum / (i - 1)) + 1;
	ok[id(sum + 1, 0)][sum] = 1;
	len[sum + 1] = 0;
//	rep(i, 1, n) cout << plc[i] << endl;
    for (int i = sum + 1; i; --i)
    {
        if (i <= sum) rep(j, 0, len[i]) ok[id(i, j)] = ((ok[id(i, j)] >> pre[i]) << pre[i]);
        if (can[i]) rep(j, 1, len[i]) ok[id(i, j)] |= ok[id(i, j - 1)];// cerr << "fdsfds" << i << endl;}
        if (i > 1) rep(j, 0, len[i]) ok[id(i - 1, j)] = (ok[id(i, j)] >> j);
//        rep(j, 0, len[i]) cout << i << ' ' << j << ' ' << ok[id(i, j)] << '\n';
    }
    rep(x, a[st[1]], sum) if (ok[id(1, x)][x])
    {
        cout << x << '\n';
        int ppt = x;
        rep(i, 1, sum)
        {
            if (can[i]) while (x > 0 && ok[id(i, x - 1)][ppt]) stk[++r] = i, --x;
            ppt += x;
        }
  //      cerr << "OK" << endl;
        x = r;
        rep(i, 1, n) pos[i] = st[i], now[i] = a[st[i]];
   //     rep(i, 1, r) cout << stk[i] << ' '; cout << endl;
        rep(i, 1, x)
        {
            cout << stk[i] << ' ';
            rep(j, 1, stk[i]) cout << pos[j] << ' ', --now[j];
            cout << '\n';
    //        cout << "gfdgfdgfd" << endl;
            int le = stk[i], re = stk[i], asd = now[stk[i]];
            while (le > 1 && now[le - 1] == asd) --le;
            while (re < n && now[re + 1] == asd + 1) ++re;
            for (; le < re; ++le, --re) swap(now[le], now[re]), swap(pos[le], pos[re]);
        }
        return 0;
    }
    cout << "-1\n";
	return 0;
}