#include<stdio.h>

#define max 1000100
#define inf 1LL * 1000000000 * 1000000000

struct nod
{
	long long val;
	long f[2];
} roads[2*max];

long n,k,p,l[2],r[2],q[2][max],lg[max];
long long b[max],m,sol;

void df(long pos,long long code,long lvl)
{
	if(roads[pos].f[0])
	{
		df(roads[pos].f[0],code*2,lvl+1);
		df(roads[pos].f[1],code*2+1,lvl+1);
		return;
	}
	lg[pos]=lvl;
	b[pos]=code;
}

void solve()
{
	k=n;
	l[0]=l[1]=1;
	r[0]=n;
	while(l[0]+l[1]<=r[0]+r[1])
	{
		++k;
		for(int j=0;j<2;j++)
		{
			p=0;
			m=inf;
			for(int i=0;i<2;i++)
		     
				if(roads[q[i][l[i]]].val <m && l[i]<=r[i])
				{
					p=i;
					m=roads[q[i][l[i]]].val;
				}
				roads[k].f[j]=q[p][l[p]];
				roads[k].val+=roads[q[p][l[p]]].val;
				l[p]++;
		}
		sol+=roads[k].val;
		q[1][++r[1]]=k;
	}
	df(k,0,0);
}

int main()
{
	freopen("huffman.in","r",stdin);
	freopen("huffman.out","w",stdout);

	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&roads[i].val);
		q[0][i]=i;
	}
	solve();
	printf("%lld\n",sol);
	for(int i=1;i<=n;i++)
		printf("%d %d\n",lg[i],b[i]);
	return 0;
}