#include <fstream>
#include <queue>

using namespace std;
const int nmax = 1e6;

queue < int > q1, q2;

struct node {
    long long val;
    int st, dr;
} a[2 * nmax];

long long code[nmax];
int len[nmax];
int n;


int minim () {
    int r;
    if ( q2.size () == 0 || ( q1.size() > 0 && a[q1.front()].val < a[q2.front()].val ) ) {
        r = q1.front ();
        q1.pop ();
    } else {
        r = q2.front ();
        q2.pop ();
    }
    return r;
}

void dfs ( int node, long long cod, int lun ) {
    if ( node == -1 )
        return;
    if ( node < n ) {
        code[node] = cod;
        len[node] = lun;
    }
    dfs ( a[node].st, cod * 2, lun + 1 );
    dfs ( a[node].dr, cod * 2 + 1, lun + 1 );
}

ifstream fin ( "huffman.in" );
ofstream fout ( "huffman.out" );

int main() {
    fin >> n;

    for ( int i = 0; i < 2 * n; i++ )
        a[i].st = a[i].dr = -1;

    for ( int i = 0; i < n; i++ ) {
        fin >> a[i].val;
        q1.push ( i );
    }

    int ind = n;
    while ( q1.size() + q2.size() >= 2 ) {
        int x = minim (), y = minim ();
        a[ind].val = a[x].val + a[y].val;
        a[ind].st = x;
        a[ind].dr = y;
        q2.push ( ind );
        ind++;
    }

    dfs ( ind - 1, 0, 0 );

    long long s = 0;
    for ( int i = 0; i < n; i++ )
        s += ( long long ) a[i].val * len[i];

    fout << s << '\n';
    for ( int i = 0; i < n; i++ )
        fout << len[i] << ' ' << code[i] << '\n';



    return 0;
}