#include<iostream>
#include<fstream>
#include<queue>
using namespace std;

const long long N = 3000010;

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

struct per {
    long long val;
    int poz;
};

long long n,nr,bz[N],smax,vall[N];
int fs[N],fd[N],val[N];
queue<per> q1,q2;

inline void cr(const per &a, const per &b) {
    per t;

    t.val = a.val + b.val; t.poz = ++nr;
    fd[nr] = a.poz;
    fs[nr] = b.poz;

    if(vall[nr]==0)
        vall[nr] = t.val;

    if(q1.empty() && q2.empty())
        return;

    q2.push(t);
}

void df(int nod, int niv, long long b10) {

    if(nod!=nr)
        smax += vall[nod];

    if(nod<=n) {
        val[nod] = niv;
        bz[nod] = b10;

        return;
    }

    df(fd[nod], niv+1, b10*2 + 1);
    df(fs[nod], niv+1, b10*2);
}

int main() {
    int i,a;
    per t,t1,t2;

    in >> n;

    for(i=1;i<=n;++i) {
        in >> a;

        vall[i]=a;

        t.poz = i; t.val = a;
        q1.push(t);
    }

    nr = n;

    while(!q1.empty() || !q2.empty()) {
        if(q1.empty()) {
            t1=q2.front();
            q2.pop();

            t2=q2.front();
            q2.pop();

            cr(t1,t2);

            continue;
        }
        if(q2.empty()) {
            t1=q1.front();
            q1.pop();

            t2=q1.front();
            q1.pop();

            cr(t1,t2);

            continue;
        }

        if(q1.front().val > q2.front().val) {
            t1 = q2.front();
            q2.pop();
        }
        else {
            t1=q1.front();
            q1.pop();
        }

        if(q1.empty()) {
            t2 = q2.front();
            q2.pop();

            cr(t1,t2);

            continue;
        }
        if(q2.empty()) {
            t2 = q1.front();
            q1.pop();

            cr(t1,t2);
            continue;
        }

        if(q1.front().val > q2.front().val) {
            t2 = q2.front();
            q2.pop();
        }
        else {
            t2 = q1.front();
            q1.pop();
        }

        cr(t1,t2);
    }

    df(nr,0,0);

    out << smax << "\n";

    for(i=1;i<=n;++i)
        out << val[i] << " " << bz[i] << "\n";

    return 0;
}