//poj 4014

//sep9

#include <iostream>

#include <algorithm>

using namespace std;

int n;

struct DICE

{

	int ids;

	int num;

	int a[128];

}d[1024];

int cmp1(DICE x,DICE y)

{

	return x.num<y.num;

}

int cmp2(DICE x,DICE y)

{

	return x.ids<y.ids;

}

int main()

{

	scanf("%d",&n);

	int sum=0;

	double ans=0;

	for(int i=1;i<=n;++i){

		scanf("%d",&d[i].num);

		sum+=d[i].num;

		d[i].ids=i;

	}

	sort(d+1,d+1+n,cmp1);

	for(int i=1;i<=n;++i)

		for(int j=1;j<=d[i].num;++j){

			d[i].a[j]=sum--;

			ans+=d[i].a[j]*1.0/d[i].num;

		}

	sort(d+1,d+1+n,cmp2);

	printf("%.5lf\n",ans);

	for(int i=1;i<=n;++i){

		for(int j=1;j<=d[i].num;++j)

			printf("%d ",d[i].a[j]);

		printf("\n");

	}

	return 0;

}