#include <fstream>
#include <stack>
#include <queue>
#include <string.h>
using namespace std;

long N;

struct TNod;
typedef TNod *PNod;
struct TNod
{
 PNod Left,Right;
 long Index;
 long Val;
};

long T;
long long B[1000005];
long LenB[1000005];

void CreazaSolutie(PNod R,long CodLen,long CodRep)
{
 if (R->Index >= 0)
   {
    LenB[R->Index] = CodLen;
    B[R->Index] = CodRep;
    T += R->Val * CodLen;
    return;
   }
 CreazaSolutie(R->Left,CodLen + 1,CodRep << 1);
 CreazaSolutie(R->Right,CodLen + 1,(CodRep << 1) | 1);
}

void AlegeNodMin(queue<PNod> &QFrunza,queue<PNod> &QNod,PNod &n1,PNod &n2)
{
 if (QFrunza.size() == 0)
   {
    n1 = QNod.front();
    QNod.pop();
    n2 = QNod.front();
    QNod.pop();
    return;
   }
 if (QNod.size() == 0)
   {
    n1 = QFrunza.front();
    QFrunza.pop();
    n2 = QFrunza.front();
    QFrunza.pop();
    return;
   }
 if (QFrunza.front()->Val < QNod.front()->Val)
   {
    n1 = QFrunza.front();
    QFrunza.pop();
    if (QFrunza.size() == 0)
      {
       n2 = QNod.front();
       QNod.pop();
       return;
      }
    if (QFrunza.front()->Val < QNod.front()->Val)
      {
       n2 = QFrunza.front();
       QFrunza.pop();
      }
     else
      {
       n2 = QNod.front();
       QNod.pop();
      }
   }
  else
   {
    n1 = QNod.front();
    QNod.pop();
    if (QFrunza.front()->Val < QNod.front()->Val)
      {
       n2 = QFrunza.front();
       QFrunza.pop();
      }
     else
      {
       n2 = QNod.front();
       QNod.pop();
      }
   }
}

int main(void)
{
 queue<PNod> QFrunza,QNod;
 long i;
 fstream fin("huffman.in",ios::in);
 fstream fout("huffman.out",ios::out);
 fin >> N;
 for (i = 0;i < N;i += 1)
  {
   PNod n = new TNod();
   n->Left = 0;
   n->Right = 0;
   n->Index = i;
   fin >> n->Val;
   QFrunza.push(n);
  }
 while ((QFrunza.size() != 0) || (QNod.size() != 1))
  {
   PNod b1,b2,bn;
   AlegeNodMin(QFrunza,QNod,b1,b2);
   bn = new TNod();
   bn->Left = b1;
   bn->Right = b2;
   bn->Index = -1;
   bn->Val = b1->Val + b2->Val;
   QNod.push(bn);
  }
 CreazaSolutie(QNod.front(),0,0);
 fout << T << "\n";
 for (i = 0;i < N;i += 1)
  {
   fout << LenB[i] << " " << B[i] << "\n";
  }
 fin.close();
 fout.close();
 return 0;
}