#include<bits/stdc++.h> using namespace std; int main(){ int n; cin >> n; int d[n+1] = {0}; int s = 0; int r = 0,b = 0; while(s != n){ r++; if(r > n){ r = 1; } if(d[r] == 0){ b++; if(b == 3){ d[r] = 1; b = 0; s++; } } } for(int i = 1;i <= n;i++){ if(d[i] == 0){ cout << i; } } return 0; }