#include <iostream>
#include <cstdio>
#include <queue>
#define NMAX 2000005

using namespace std;

int n, nAux;
long long sol, dist[NMAX];
pair <long long, long long> tati[NMAX];
queue <pair <long long, long long> >q1, q2;


void read()
{
    scanf("%d", &n);
    nAux = n;
    long long x;
    for(int i=1; i<=n; ++i)
    {
        scanf("%lld", &x);
        q1.push(make_pair(x, i));
    }
}

pair <long long, long long> minim()
{
    pair <long long, long long> x;
    if(q1.empty())
    {
        x=q2.front();
        q2.pop();
        return x;
    }
    if(q2.empty())
    {
        x=q1.front();
        q1.pop();
        return x;
    }
    if(q1.front() <= q2.front())
    {
        x=q1.front();
        q1.pop();
        return x;
    }
    else
    {
        x=q2.front();
        q2.pop();
        return x;
    }
}

void codare()
{
    pair <long long, long long> x1, x2;
    while(q1.size() + q2.size() > 1)
    {
        x1 = minim();
        x2 = minim();

        q2.push(make_pair(x1.first + x2.first, ++n));
        sol += x1.first + x2.first;

        tati[(int)x1.second].first = tati[(int)x2.second].first = n;

        tati[(int)x1.second].second = 0;
        tati[(int)x2.second].second = 1;
    }
}

void afisare()
{
    printf("%lld\n", sol);

    for(int i=n-1; i>=1; i--)
    {
        tati[i].second|=(1LL*(tati[tati[i].first].second<<1));
        dist[i]=1+dist[tati[i].first];
    }
    for(int i=1;i<=nAux;i++)
    {
        printf("%lld %lld\n",dist[i],tati[i].second);
    }

}

int main()
{
    freopen("huffman.in", "r", stdin);
    freopen("huffman.out", "w", stdout);
    read();
    codare();
    afisare();
    return 0;
}