#include<bits/stdc++.h> using namespace std; int main() { vector<int> beautiful_numbers; for (int i = 1; beautiful_numbers.size() < 100000; ++i) { if (i % 3 == 0 || i % 5 == 0) { beautiful_numbers.push_back(i); } } int N; while (cin >> N) { cout << beautiful_numbers[N - 1] << endl; } return 0; }