#include <bits/stdc++.h> using namespace std; const int N = 100005; int a[N]; int main() { //cin.tie(0); int c = 0; for(int i = 1;; ++i){ if(i % 3 == 0 || i % 5 == 0) a[++c]=i; if(c > N) break; } int n; while(~scanf("%d", &n)){ cout << a[n] << '\n'; } return 0; }