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

using namespace std;

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

bool stiva[123];
int istiva;

class huffman{
public:
    huffman *lf, *rg;
    bool is_leaf;
    unsigned long long times;
    huffman() : lf(NULL), rg(NULL), is_leaf(true), times(NULL) {}
    huffman(unsigned long long _times) : lf(NULL), rg(NULL), is_leaf(true), times(_times) {}
    huffman(unsigned long long _times, huffman *_lf, huffman *_rg) : lf(_lf), rg(_rg), is_leaf(false), times(_times) {}
};

unsigned long long rez(huffman *root){
    if(root -> is_leaf){
        return 0;
    }
    return rez(root -> lf) + rez(root -> rg) + root -> times;
}

int b2_to_b10(bool *begin, bool *end){
    int rez = 0;
    for(int i = istiva - 1; begin != end; i--){
        rez += (1 << i) * (*begin++);
    }
    return rez;
}

void go_lf_rg(huffman *root){
    if(root -> is_leaf){
        fout<<istiva<<" " <<b2_to_b10(stiva, stiva + istiva)<<"\n";
        return;
    }
    stiva[istiva++] = 0;
    go_lf_rg(root -> lf);
    istiva--;
    stiva[istiva++] = 1;
    go_lf_rg(root -> rg);
    istiva--;
    return;
}

int main(){
    huffman *root, *lf, *rg;
    queue < int > qf;
    queue < huffman* > qn;
    int n, x;
    fin>>n;
    while(n--){
        fin>>x;
        qf.push(x);
    }
    while(true){
        if(qf.empty()){
            lf = qn.front();
            qn.pop();
        }
        else if(qn.empty()){
                lf = new huffman(qf.front());
                qf.pop();
            }
            else if(qf.front() <= qn.front() -> times){
                    lf = new huffman(qf.front());
                    qf.pop();
                }
                else{
                    lf = qn.front();
                    qn.pop();
                }



        if(qf.empty() && qn.empty()){
            root = lf;
            break;
        }



        if(qf.empty()){
            rg = qn.front();
            qn.pop();
        }
        else if(qn.empty()){
                rg = new huffman(qf.front());
                qf.pop();
            }
            else if(qf.front() <= qn.front() -> times){
                    rg = new huffman(qf.front());
                    qf.pop();
                }
                else{
                    rg = qn.front();
                    qn.pop();
                }
        root = new huffman(lf -> times + rg -> times, lf, rg);
        qn.push(root);
    }
    istiva = 0;
    fout<<rez(root)<<"\n";
    go_lf_rg(root);
	return 0;
}