#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>

#define NMAX 1000005

using namespace std;

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

struct Huffman {
	int son[2];
}Nodes[2*NMAX];

queue < int > Q_first , Q_second;
int A , B , val[2*NMAX];
int N , K,Len[NMAX];
long long Code[NMAX] , Answer;
void Extract ( int &V)
{
	if ( Q_second.empty() and Q_first.empty() )
		return ; 
	  if ( !Q_second.empty())
	  {
		  if ( !Q_first.empty() )
		  {
		  if ( val[Q_first.front()]< val[Q_second.front()] ) 
			   V = Q_first.front() , Q_first.pop();
		  else
		       V = Q_second.front() , Q_second.pop();
		  }
		  else V = Q_second.front() , Q_second.pop();
	  }
	  else V = Q_first.front() , Q_first.pop();
}
void DepthFirstSearch ( int i , long long config , int lvel )
{
	if ( Nodes[i].son[0] )
	{ 
		DepthFirstSearch ( Nodes[i].son[0] , ( config <<1 ), lvel + 1 ); 
		DepthFirstSearch ( Nodes[i].son[1] , ( config <<1 ) + 1 , lvel + 1 );
		return ;
	}
	Len[i] = lvel;
	Code[i] = config;
}

int main ( void )
{
	int i , j , x ;
	in >> N ;
	for ( i = 1 ; i <= N ; ++i )
		in >> val[i] , Q_first.push( i);
	K = N + 1;
	for ( ; !Q_first.empty() or !Q_second.empty() ; )
	{
		Extract ( A );
		Extract ( B );
		Answer += val[A]+ val[B];
		Nodes[++K].son[0] = A;
		Nodes[K].son[1] = B;
		val[K] = val[A] + val[B];
		if ( A != 0 and B !=0 )
		Q_second.push( K );
		else --K,Answer -= val[A];
		A = B = 0 ;
	}
	DepthFirstSearch ( K , 0 , 0  );
	out << Answer << "\n";
	for ( i = 1 ; i <= N ; ++i )
		out << Len[i] << " " <<Code[i] << "\n";
	in.close();
	out.close();
	return 0;
}