#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
#include <iomanip>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETSEGMENT( A , SEPARATOR ) string A; getline( cin , A , SEPARATOR ) 
#define GETLINE( A ) string A; getline( cin , A ) 
#define FOR_LL( VAR , INITIAL , FINAL_PLUS_ONE ) for( ll VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ ) 
#define RETURN( LL , ANSWER ) const LL answer_for_contest = ( ANSWER ); cout << answer_for_contest << endl; return 0 
#define DOUBLE( DIGITS , ANSWER ) const double answer_for_contest = ( ANSWER ); cout << fixed << setprecision( DIGITS ) << answer_for_contest << endl; return 0 

template <typename T> inline T Distance( const T& a , const ll& b ){ return a < b ? b - a : a - b; }



int main()
{

  CIN( ll ,X );
  ll walk[7] = { 2 , 2 , -1 , -1 , 2 , -1 , -1 };
  ll abs[7] = { 2 , 2 , 1 , 1 , 2 , 1 , 1 };
  ll x = 0;
  ll answer = 0;
  FOR_LL( i , 0 , 100 ){
    FOR_LL( j , 0 , 7 ){
      x += walk[j];
      answer += abs[j];
      if( x == X ){
	RETURN( ll , answer );
      }
    }
  }
  RETURN( string , "" );

}