#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <queue>
#define N 1000000

using namespace std;


struct nod{
    long long  val;
    int ord;

    struct nod *left=NULL, *right=NULL;

};

queue <struct nod> qfr,qin;
long long  v[N],s;
int l[N];


void gen( nod *x , long long vcod, int lvl ){

    if(x->ord==0){
        s+=x->val;
    }
    v[ x->ord ]=vcod;
    l[ x->ord ]=lvl;
    if(x->left==NULL && x->right==NULL){
        return;
    }else{
        if(x->left!=NULL){
            gen(x->left,2*vcod,lvl+1);
        }
        if(x->right!=NULL){
            gen(x->right,2*vcod+1,lvl+1);

        }
    }

}

int main(){
    struct nod nodx;
    int i,x,n;
    bool spy=0;

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


    scanf("%d",&n);

    for(i=1;i<=n;i++){
        scanf("%d",&x);

        nodx.val=x;
        nodx.ord=i;
        qfr.push(nodx);
    }

    while( !(qfr.size()==0 && qin.size()==1) ){

        nod *a=new nod;
        nod *b=new nod;
        nod *c=new nod;

        for(i=0;i<2;i++){

            if(qfr.empty() && qin.empty()){
                spy=1;
                break;
            }

            if(qfr.empty()){
                *b=*a;
                *a=qin.front(); qin.pop();
            }else if(qin.empty()){
                *b=*a;
                *a=qfr.front(); qfr.pop();
            }else{
                if(qfr.front().val > qin.front().val  ){
                    *b=*a;
                    *a=qin.front(); qin.pop();

                }else{
                    *b=*a;
                    *a=qfr.front(); qfr.pop();
                }
            }
        }
        if(spy==1){
            qin.push(*a);
            break;
        }

        c->val=a->val+b->val;
        c->ord=0;
        c->left=b; c->right=a;
        qin.push(*c);

    }

    nodx=qin.front();

    gen(&nodx,0,0);

    printf("%lld\n",s);

    for(i=1;i<=n;i++){
        printf("%d %lld\n",l[i],v[i]);
    }

    return 0;
}