#include <bits/stdc++.h>
using namespace std;
ifstream f("huffman.in");
ofstream g("huffman.out");
typedef long long ll;
const int nmax = 3 + 1e6;
int n, kp, st[2 * nmax], dr[2 * nmax], af1[nmax];
ll vals[2 * nmax], result, af2[nmax];
queue<int> q1, q2;
int getnew();
void dfs(int, ll, int);
int32_t main()
{
    f >> n;
    kp = n;
    for (int i = 1; i <= n; i++)
        f >> vals[i], q1.push(i);
    if (n == 1)
    {
        g << vals[1] << "\n1 1";
        return 0;
    }
    int ax1 = q1.front();
    q1.pop();
    int ax2 = q1.front();
    q1.pop();
    vals[++kp] = vals[ax1] + vals[ax2];
    st[kp] = ax1;
    dr[kp] = ax2;
    q2.push(kp);
    while (q1.size() + q2.size() > 1)
    {
        ax1 = getnew();
        ax2 = getnew();
        vals[++kp] = vals[ax1] + vals[ax2];
        st[kp] = ax1;
        dr[kp] = ax2;
        q2.push(kp);
    }
    dfs(kp, 0, 0);
    g << result << '\n';
    for (int i = 1; i <= n; i++)
        g << af1[i] << " " << af2[i] << '\n';
    return 0;
}
int getnew()
{
    int rez;
    if (q1.empty())
        rez = q2.front(), q2.pop();
    else if (q2.empty())
        rez = q1.front(), q1.pop();
    else if (vals[q1.front()] < vals[q2.front()])
        rez = q1.front(), q1.pop();
    else
        rez = q2.front(), q2.pop();
    return rez;
}
void dfs(int x, ll nr, int ct)
{
    if (st[x] == 0 && dr[x] == 0)
        result += 1ll * vals[x] * ct, af1[x] = ct, af2[x] = nr;
    else
    {
        dfs(st[x], nr * 2, ct + 1);
        dfs(dr[x], nr * 2 + 1, ct + 1);
    }
}