// Huffman cu doua cozi, O(n)

#include <fstream>
#include <iostream>
#include <queue>

using namespace std;

#define MAXN 1000100

struct NOD {
    long long v;
    int f[2]; // fiul stang, fiul drept
} nod[2 * MAXN];

int n, l[MAXN];
queue<int> q[2]; // coada frunzelor, coada nodurilor interioare
long long b[MAXN], m, lt;
ifstream fin("huffman.in");
ofstream fout("huffman.out");

void walk_tree(long poz, long long cod, long nivel) {
    if (nod[poz].f[0]) { // nod interior
        walk_tree(nod[poz].f[0], cod * 2, nivel + 1);
        walk_tree(nod[poz].f[1], cod * 2 + 1, nivel + 1);
        return;
    }
    else {              // frunza
        l[poz] = nivel; // lungimea codului
        b[poz] = cod;
    }
}

void build_tree() {
    int iqmin;
    long long m;

    for (int k = n + 1; k <= 2 * n - 1; k++) {
        for (int fiu = 0; fiu <= 1; fiu++) {
            m = 1e18;
            for (int iq = 0; iq <= 1; iq++) {
                if (not q[iq].empty())
                    if (nod[q[iq].front()].v < m) {
                        iqmin = iq;
                        m = nod[q[iq].front()].v;
                    }
            }
            nod[k].v += nod[q[iqmin].front()].v;
            cout << nod[q[iqmin].front()].v << endl;
            nod[k].f[fiu] = q[iqmin].front();
            q[iqmin].pop();
        }
        lt += nod[k].v;
        q[1].push(k);
    }
}

int main() {
    fin >> n;
    for (int i = 1; i <= n; i++) {
        fin >> nod[i].v;
        q[0].push(i);
    }
    build_tree();
    walk_tree(2 * n - 1, 0, 0);
    fout << lt << '\n';
    for (int i = 1; i <= n; i++) {
        fout << l[i] << ' ' << b[i] << '\n';
    }
    return 0;
}