#include <fstream>

using namespace std;

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

const int N = 1000100;
const long long inf = (1LL << 62);

struct nod {
    long long v;
    int f[2];
};

int n, i, j, k, p, l[2], r[2], q[2][N], lg[N];
long long b[N], m, sol;

nod v[2 * N];

void df(int poz, long long cod, int niv) {
    if (v[poz].f[0]) {
        df(v[poz].f[0], cod * 2, niv + 1);
        df(v[poz].f[1], cod * 2 + 1, niv + 1);
        return;
    }
    lg[poz] = niv;
    b[poz] = cod;
}

int main() {
    fin >> n;
    for (i = 1; i <= n; ++i) {
        fin >> v[i].v;
        q[0][i] = i;
    }
    k = n;
    l[0] = l[1] = 1;
    r[0] = n;
    while (l[0] + l[1] <= r[0] + r[1]) {
        k++;
        for (j = 0; j < 2; ++j) {
            p = 0;
            m = inf;
            for (i = 0; i < 2; ++i) {
                if (v[ q[i][ l[i] ] ].v < m && l[i] <= r[i]) {
                    p = i;
                    m = v[ q[i][ l[i] ] ].v;
                }
            }
            v[k].f[j] = q[p][ l[p] ];
            v[k].v += v[ q[p][ l[p] ] ].v;
            l[p]++;
        }
        sol += v[k].v;
        q[1][ ++r[1] ] = k;
    }
    df(k, 0, 0);
    fout << sol << "\n";
    for(i=1; i<=n; i++) {
        fout << lg[i] << ' ' << b[i] << "\n";
    }
    return 0;
}