#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define mp make_pair
#define dbg(x) cout << #x <<": " << x << "\n";
#define sz(x) ((int)x.size())

using ll = long long;

const string fn = "huffman";
ifstream fin(fn + ".in");
ofstream fout(fn + ".out");

const int mxn = 1e6 + 5;

int n, st[(mxn << 1)], dr[(mxn << 1)];
ll  nr[mxn + 5],ans[mxn + 1], lg[(mxn << 1)], rez;


queue<int> q1, q2;

void dfs(int nod, ll mask, int d)
{

    if(nod <= n)
    {
        ans[nod] = mask;
        lg[nod] = d;
        rez += nr[nod] * d;
    }
    else
    {
        if(st[nod])
            dfs(st[nod], mask << 1LL, d + 1);
        if(dr[nod])
            dfs(dr[nod], mask << 1LL | 1LL, d + 1);
    }

}


int best()
{
    int ac;
    if(q2.empty())
    {
        ac = q1.front();
        q1.pop();
        return ac;
    }
    if(q1.empty())
    {
        ac = q2.front();
        q2.pop();
        return ac;
    }
    if(nr[q1.front()] < nr[q2.front()])
    {
        ac = q1.front();
        q1.pop();
        return ac;
    }
    else
    {
        ac = q2.front();
        q2.pop();
        return ac;
    }
}



int main()
{

    ios_base::sync_with_stdio(false);
    cin.tie();

    fin >> n;
    for(int i = 1; i <= n; ++i)
    {
        fin >> nr[i];
        q1.push(i);
    }

    int i = n;
    while(sz(q1) + sz(q2) > 1)
    {
        int x = best(), y = best();
        nr[++i] = nr[x] + nr[y];
        st[i] = x, dr[i] = y;
        q2.push(i);
    }
    dfs(q2.front(), 0, 0);
    fout << rez << '\n';
    for (int i = 1; i <= n; ++i)
        fout << lg[i] << ' ' << ans[i] << '\n';

    return 0;
}