UVA 11150 - Cola

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main(int argc, char *argv[]){
  int n;
  while(cin>>n){
    int total=n;
    int empty=n;
    int remain;

    while (empty>=3){
      remain = empty/3; 
      empty = empty%3;
       total += remain;
       empty += remain;
     }
 
     if (empty==2){
       total++;
     } 
     
     cout << total << endl;
   }
   return 0;
 }