#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int MAXN = 15001;
vector<bitset<MAXN>>dp[MAXN]; //this many items
bitset<MAXN>full[MAXN];
int a[MAXN],b[MAXN+1],c[MAXN],cnt[MAXN];
int main()
{
owo
int n,m,s = 0;
cin>>n;
for(int i=0;i<n;i++){
cin>>a[i];
cnt[a[i]]++;
s+=a[i];
}
int cur = n,sum = 0;
for(int i=1;i<MAXN;i++){
sum+=cnt[i]*i;
cur-=cnt[i];
c[i] = sum + cur*i;
}
int prev = 0;
for(int i=1;i<MAXN;i++){
full[i] = full[i-1];
while(prev<=c[i]){
full[i][prev] = 1;
prev++;
}
prev--;
}
cin>>m;
for(int i=0;i<m;i++)cin>>b[i];
sort(b,b+m,greater<int>());
dp[0].resize(1);
dp[0][0][0] = 1;
for(int i=0;i<m;i++){
int k = s/b[i];
dp[i+1].resize(k+1);
for(int j=0;j<sz(dp[i]);j++)dp[i+1][j] = dp[i][j];
for(int j=1;j<=k;j++){
dp[i+1][j] |= dp[i+1][j-1] << b[i];
dp[i+1][j] &= full[j];
}
}
vector<int>item;
cur = -1;
for(int i=0;i<sz(dp[m]);i++){
if(dp[m][i][s]){
cur = i;
break;
}
}
if(cur==-1){
cout<<-1;
return 0;
}
for(int i=m;i>0;i--){
//cout<<cur<<" "<<sz(dp[i])<<'\n';
while(s >= b[i-1] && cur){
if(dp[i][cur][s]){
if(dp[i][cur-1][s-b[i-1]]){
item.pb(b[i-1]);
cur--;
s-=b[i-1];
}else{
if(dp[i-1][cur-1][s-b[i-1]]){
item.pb(b[i-1]);
cur--;
s-=b[i-1];
}
break;
}
}
}
}
multiset<pii,greater<pii>>ss;
for(int i=0;i<n;i++)ss.insert({a[i],i});
cout<<sz(item)<<'\n';
for(int x:item){
vector<int>sol,addback;
for(int i=0;i<x;i++){
int j = ss.begin()->se;
ss.erase(ss.begin());
sol.pb(j+1);
a[j]--;
if(a[j])addback.pb(j);
}
for(int x:addback)ss.insert({a[x],x});
cout<<x<<" ";
for(int x:sol)cout<<x<<" ";
cout<<'\n';
}
}
