#include <stdio.h>
#include <queue>
#include <limits>
#include <fstream>

#define int64 long long int
#define arb node*

using namespace std;

typedef struct node {
    int64 frecv;
    arb left;
    arb right; 
    int poz;       
} node;

queue<arb> A;
queue<arb> Init;
int n;
int64 S;
int V_h[1000001];
int64 V_val[1000001];

void read_() {
     char buff;
     ifstream in("huffman.in");
          
     in >> n;
     for (int i = 0; i < n; i++) {
         arb El = new node();
         in >> El->frecv;         
         El->poz = i;
         Init.push(El);
     } 
     in.close();
}

void solve_() {
     arb El = new node();
     El->frecv = numeric_limits<int64>::max();
     Init.push(El);
     
     node *El1, *El2, *Fin;
     for (int i = 1; i < n; i++) { 
         if (A.size() == 0 || (A.front())->frecv > (Init.front())->frecv) {
             El1 = Init.front();
             Init.pop();       
         }
         else  {
             El1 = A.front();
             A.pop();    
         } 
         
         if (A.size() == 0 || (A.front())->frecv > (Init.front())->frecv) {
             El2 = Init.front();
             Init.pop();       
         }
         else  {
             El2 = A.front();
             A.pop();    
         } 
         
         Fin = new node();
         Fin->frecv = El1->frecv + El2->frecv;
         Fin->left = El1;
         Fin->right = El2; 
         
         A.push(Fin);  
         S += Fin->frecv; 
         //printf("%lld %lld -> %lld\n", El1->frecv, El2->frecv, Fin->frecv);  
     }
}

void dfs_(arb H, int h, int64 val) {         
     if (H->left != NULL) {
         dfs_(H->left, h + 1, val << 1);
     }
     if (H->right != NULL) {
         dfs_(H->right, h + 1, (val << 1) + 1);
     }   
     if (H->left == NULL && H->right == NULL) { 
         V_h[H->poz] = h;
         V_val[H->poz] = val;      
     }
}

void print_() {   
    ofstream out("huffman.out");  
    out << S << endl;
    for (int i = 0; i < n; i++) {
        out << V_h[i] << " " << V_val[i] << endl;
    }     
    out.close();
}

int main() {
    //freopen("huffman.in", "r", stdin);
    //freopen("huffman.out", "w", stdout);
    
    int start,end;
    int dif;
    start = clock();
    read_();  
    end = clock();      
    dif = end - start;
    //printf ("\nIt took me %d -> read.\n", dif );
    
    start = clock();
    solve_();
    end = clock();      
    dif = end - start;
    //printf ("\nIt took me %d -> solve.\n", dif );
        
    start = clock();
    dfs_(A.front(), 0, 0);
    end = clock();
    dif = end - start;
   // printf ("\nIt took me %d -> dfs.\n", dif );
    
    start = clock();    
    print_();
    end = clock();
    dif = end - start;
    //printf ("\nIt took me %d -> print.\n", dif );
    
    return 0;
}