#include <bits/stdc++.h>
#define pii pair<int,int>
#define s1 first
#define s2 second
using namespace std;
int n,a[100011],tot,m,b[100011],sum[15011],buc[15011],nxt[15011];
vector<bitset<15011> > dp[15011];
bitset<15011> I;vector<int> v,tmp;
priority_queue<pii > pq;
int main()
{
	scanf("%d",&n);for(int i=1;i<=n;++i)scanf("%d",a+i),++buc[a[i]],tot+=a[i];
	scanf("%d",&m);for(int i=1;i<=m;++i)scanf("%d",b+i);
	int cnt=n;
	for(int i=1;i<=15000;++i)
	{
		sum[i]=sum[i-1]+cnt;
		cnt-=buc[i];
	}
	for(int i=0;i<15011;++i)I[i]=1;
	dp[0].resize(m+1);dp[0][m][0]=1;
	for(int i=1;i<=tot+1;++i)
	{
		for(int j=int(dp[i-1].size())-2;j>0;--j)dp[i-1][j]|=dp[i-1][j+1];
		if(!dp[i-1].size())break;
		while(!dp[i-1].back().any())dp[i-1].pop_back();
		dp[i-1].shrink_to_fit();
		if(dp[i-1].size()>1&&dp[i-1][1][tot])break;
		if(i<=tot)
		{
			dp[i].resize(dp[i-1].size());
			for(int j=1;j<dp[i-1].size();++j)dp[i][j]=(dp[i-1][j]<<b[j])&(I>>15011-sum[i]-1);
		}
	}
	int I=-1,J=1,K=tot;
	for(int i=1;i<=tot;++i)
	{
		if(J<dp[i].size()&&dp[i][J][K]){I=i;break;}
	}
	if(!~I){printf("-1\n");return 0;}
	printf("%d\n",I);
	while(I!=0)
	{
		while(J<dp[I].size()-1&&dp[I][J+1][K])++J;
		v.push_back(b[J]);--I;K-=b[J];
	}
	for(int i=1;i<=n;++i)pq.push(pii(a[i],i));
	sort(v.begin(),v.end());
	for(int i=0;i<v.size();++i)
	{
		printf("%d ",v[i]);
		tmp.clear();
		for(int _=0;_<v[i];++_)tmp.push_back(pq.top().s2),pq.pop();
		for(int x:tmp)--a[x],printf("%d ",x);putchar(10);
		for(int x:tmp)pq.push(pii(a[x],x));
	}return 0;
}