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

using namespace std;

ifstream f("huffman.in");
ofstream g("huffman.out");

int const NMax = 1001000;
int V[2*NMax], G[2*NMax][3], C[2*NMax], L[2*NMax];
int n, nr, lg;
queue <int> Q1, Q2;

void Read()
{
    f>>n;
    for(int i=1; i<=n; i++)
        f>>V[i];
}

int GetMin()
{
    int x, y;

    if(Q1.size() && Q2.size()){
        x = Q1.front(); y = Q2.front();
        if(V[x] < V[y]){
            Q1.pop();
            return x;
        }
        else{
            Q2.pop();
            return y;
        }
    }

    if(Q1.size()){
        x = Q1.front();
        Q1.pop();
        return x;
    }

    y = Q2.front();
    Q2.pop();
    return y;
}

void DFS(int nod, int cod, bool side)
{
    if(G[nod][0] == 0){
        C[nod] = (cod << 1) + side;
        return;
    }

    lg += V[nod];
    cod = (cod << 1) + side;

    int son1, son2;
    son1 = G[nod][0];
    son2 = G[nod][1];
    L[son1] = L[son2] = L[nod] + 1;

    DFS(G[nod][0], cod, 0);
    DFS(G[nod][1], cod, 1);
}

void Solve()
{
    int i, j, x, y;

    for(i=1; i<=n; i++)
        Q1.push(i);

    nr = n;
    while(Q1.size() + Q2.size() > 1){
        nr++;
        x = GetMin();
        y = GetMin();

        V[nr] = V[x] + V[y];
        Q2.push(nr);

        G[nr][0] = x;
        G[nr][1] = y;
    }

    DFS(nr, 0, 0);
}

void Print()
{
    g<<lg<<"\n";
    for(int i=1; i<=n; i++)
        g<<L[i]<<" "<<C[i]<<"\n";
}

int main()
{
    Read();
    Solve();
    Print();
    return 0;
}