#include <bits/stdc++.h>

using namespace std;

ifstream fin("huffman.in");
ofstream fout("huffman.out");
const int NMAX = 1e6+100;
int n;
long long sum;

struct nod
{
    long long val;
    int left, right, ad;
}w[2*NMAX];

///0 pe stanga, 1 pe dreapta
void dfs(int nod, int ad, long long val)
{
    if(nod > 0)
    {
        w[nod].val = val;
        dfs(w[nod].left, ad+1, val<<1);
        dfs(w[nod].right, ad+1, (val+1)<<1);
    }
}

void huffman()
{
    int i, j, stop, first, second;
    i = 1;
    j = n+2;
    stop = n+1;

    while(i < n || j < stop)
    {
        if(j <= stop && w[j].val < w[i].val)
            first = j, ++j;
        else first = i, ++i;

        if(j <= stop && w[j].val < w[i].val)
            second = j, ++j;
        else second = i, ++i;

        w[++stop].val = w[first].val + w[second].val;
        w[stop].left = first;
        w[stop].right = second;
        sum += w[stop].val;
    }

//    while(j + 1 <= stop)
//    {
//        w[++stop].val = w[j].val + w[j+1].val;
//        w[stop].left = j;
//        w[stop].right = j+1;
//        j += 2;
//    }
    dfs(stop, 0ll, 0ll);
}
int main()
{
    fin >> n;
    for(int i = 1; i <= n; ++i)
        fin >> w[i].val;

    huffman();

    fout << sum << '\n';

    for(int i = 1; i <= n; ++i)
        fout << w[i].ad << ' ' << w[i].val << '\n';
    return 0;
}