#include<stdio.h>
#define Nmax 1000010

struct Arb { int key; long long cost; Arb *st,*dr;} *A[Nmax<<1];

int n,Q1[Nmax],Q2[Nmax],i,L[Nmax],R,nod1,nod2,p,u,cst;
long long Sum,Cod[Nmax];

void dfs ( Arb *nod, long long cod, int mSize)
{
	if(nod->st==NULL) 
	{
		L[nod->key]=mSize;
		Cod[nod->key]=cod;
		return ;
	}
	
	dfs(nod->st,cod<<1,mSize+1);
	dfs(nod->dr,(cod<<1)+1,mSize+1);
}

void add()
{
	R++;
	A[R]=new Arb;
	A[R]->cost = A[nod1]->cost + A[nod2]->cost;
	A[R]->st=A[nod1];
	A[R]->dr=A[nod2];
}

int main()
{
	freopen("huffman.in","r",stdin);
	freopen("huffman.out","w",stdout);
	
	scanf("%d",&n);

	for(i=1;i<=n;i++)
	{
		scanf("%d",&cst);
		Q1[i]=i;
		A[i] = new Arb;
		A[i]->key=i;
		A[i]->cost=cst;
		A[i]->st=A[i]->dr=NULL;
	}
	
	if(n==1) {printf("0\n1 0"); return 0;}
	
	R=n;
	nod1=1; nod2=2;
	add();
	
	i=3; Q2[1]=R; p=u=1;
	
	while(i<=n)
	{
		nod1=Q1[i];
		nod2=Q2[p];
		
		if(i+1<=n && A[Q1[i+1]]->cost < A[nod2]->cost)
		{
			nod2=Q1[i+1];
			i+=2;
		}
		else if(p+1<=u && A[Q2[p+1]]->cost < A[nod1]->cost)
		{
			nod1=Q2[p+1];
			p+=2;
		}
		else i++,p++;			
		
		add();		
		Q2[++u]=R;		
	}
	
	while(p!=u)
	{
		nod1=Q2[p];
		nod2=Q2[p+1];
		p+=2;
		
		add();
		Q2[++u]=R;
	}
	
	dfs(A[R],0,0);
	
	for(i=1;i<=n;i++)
		Sum+=L[i]*A[i]->cost;
	printf("%lld\n",Sum);
	
	for(i=1;i<=n;i++)
		printf("%d %lld\n",L[i],Cod[i]);
	
	return 0;
}