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

using namespace std;

ofstream g("huffman.out");

int const NMax = 1001000;
long long V[2*NMax], C[2*NMax];
int G[2*NMax][3], L[2*NMax];
long long n, nr, lg, st1, st2, dr1, dr2, pos;
int Q1[NMax], Q2[2*NMax];
long long const oo = 1LL<<62;
int const Buffer_Size = 100000;
char Buffer[Buffer_Size];

void read(long long & nr)
{
    nr = 0;
    while(Buffer[pos] < '0' || Buffer[pos] > '9'){
        pos++;
        if(pos == Buffer_Size){
            fread(Buffer, 1, Buffer_Size, stdin);
            pos = 0;
        }
    }
    while(Buffer[pos] >= '0' && Buffer[pos] <= '9'){
        nr = nr*10 + Buffer[pos++] - '0';
        if(pos == Buffer_Size){
            fread(Buffer, 1, Buffer_Size, stdin);
            pos = 0;
        }
    }
}
void Read()
{
    freopen("huffman.in", "r", stdin);
    fread(Buffer, 1, Buffer_Size, stdin);

    read(n);
    for(int i=1; i<=n; i++)
        read(V[i]);
}

inline int GetMin()
{
    int x, y;

    x = Q1[st1]; y = Q2[st2];
    if(V[x] < V[y]){
        st1++;
        return x;
    }
    else{
        st2++;
        return y;
    }
}

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

    lg += V[nod];
    cod = (cod << 1) + side;
    L[G[nod][0]] = L[G[nod][1]] = L[nod] + 1;

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

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

    for(i=1; i<=n; i++)
        Q1[++dr1] = i;

    nr = n;
    st1 = st2 = 1;
    dr2 = 0;
    V[0] = oo;
    while((dr1 - st1 + 1) + (dr2 - st2 + 1) > 1){
        nr++;
        x = GetMin();
        y = GetMin();

        V[nr] = V[x] + V[y];
        Q2[++dr2] = 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;
}