#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
#define int long long
#define F first
#define S second
#define pb push_back
#define popp pop_back
#define in insert
#define endl "\n"
#define mid (l+r)/2
using namespace std;
const int N=505;
int n,A[N],m,b[N],dp[505];
int32_t main(){
ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
cin>>n;
for(int i=1;i<=n;i++) cin>>A[i];
cin>>m;
for(int i=1;i<=m;i++) cin>>b[i];
dp[0]=0;
for(int i=1;i<=n;i++) dp[i]=1e9;
for(int i=1;i<=m;i++){
for(int j=0;j+b[i]<=n;j++){
dp[j+b[i]]=min(dp[j+b[i]],dp[j]+1);
}
}
//for(int i=0;i<=7;i++) cout<<" # "<<i<<' '<<dp[i]<<endl;
if(dp[n]==1e9) cout<<-1<<endl;
else{
cout<<dp[n]<<endl;
int sz=n,idb=0,used=0;
while(sz!=0){
for(int i=1;i<=m;i++){
if(sz-b[i]>=0 && dp[sz-b[i]]+1==dp[sz]){
sz-=b[i];
++idb;
cout<<b[i]<<' ';
for(int j=1;j<=b[i];j++){
cout<<++used<<' ';
}
cout<<endl;
break ;
}
}
}
}
return 0;
}
