#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef __int128 lll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pld;
#define MAX 9223372036854775807LL
#define MIN -9223372036854775807LL
#define INF 0x3f3f3f3f3f3f3f3f
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cout << fixed; cout.precision(10);
#define sp << " "
#define en << "\n"
#define compress(v) sort(v.begin(), v.end()), v.erase(unique(v.begin(), v.end()), v.end())
ll n;
ll a[15010];
ll m;
ll b[15010];
ll sum, S[15010];
priority_queue<ll> pq;
ll now, gaet;
vector< bitset<15010> > dp[15010];
bitset<15010> tmp;
ll ans = INF;
ll I, J, K;
vector<ll> box;
priority_queue<pll> pq2;
vector<ll> ans2[15010];
int main(void)
{
fastio
cin >> n;
for(ll i = 1 ; i <= n ; i++)
{
cin >> a[i];
sum += a[i];
pq.push(a[i]);
}
cin >> m;
for(ll i = 1 ; i <= m ; i++)
cin >> b[i];
now = sum, gaet = 0;
for(ll i = sum ; i >= 1 ; i--)
{
while(!pq.empty() && pq.top() >= i)
{
now -= pq.top();
gaet++;
pq.pop();
}
S[i] = now + gaet * i;
}
for(ll i = 0 ; i <= sum ; i++)
{
dp[i].push_back(tmp);
for(ll j = 1 ; j <= m ; j++)
{
if(b[j] * i <= sum)
dp[i].push_back(tmp);
else
break;
}
}
dp[0].push_back(tmp);
for(ll j = 0 ; j < (ll)dp[0].size() ; j++)
dp[0][j].set(0, 1);
for(ll i = 1 ; i <= sum ; i++)
{
for(ll j = S[i - 1] + 1 ; j <= S[i] ; j++)
tmp.set(j, 1);
ll siz = (ll)dp[i].size() - 1;
ll siz2 = (ll)dp[i - 1].size() - 1;
for(ll j = siz ; j >= 1 ; j--)
{
if(j < siz)
dp[i][j] |= dp[i][j + 1];
if(j <= siz2)
dp[i][j] |= (dp[i - 1][j] << b[j]);
dp[i][j] &= tmp;
}
}
for(ll i = 0 ; i <= sum ; i++)
{
ll siz = (ll)dp[i].size() - 1;
for(ll j = 1 ; j <= siz ; j++)
{
if(dp[i][j][sum])
{
if(ans > i)
{
ans = i;
I = i, J = j, K = sum;
}
}
}
}
if(ans == INF)
{
cout << -1;
return 0;
}
cout << ans en;
while(1)
{
if(I == 0)
break;
if(J < (ll)dp[I].size() - 1 && dp[I][J + 1][K])
{
J = J + 1;
continue;
}
box.push_back(b[J]);
I = I - 1, K = K - b[J];
}
ll num = 1;
for(auto &i : box)
pq2.push({i, num++});
for(ll i = 1 ; i <= n ; i++)
{
vector<pll> tmp3;
for(ll j = 0 ; j < a[i] ; j++)
{
tmp3.push_back(pq2.top());
pq2.pop();
}
for(auto &j : tmp3)
{
ans2[j.se].push_back(i);
if(j.fi > 1)
pq2.push({j.fi - 1, j.se});
}
}
for(ll i = 1 ; i <= ans ; i++)
{
cout << (ll)ans2[i].size() sp;
for(auto &j : ans2[i])
cout << j sp;
cout en;
}
return 0;
}
