#include <bits/stdc++.h> using namespace std; int main() { int j; int n; int a[100005]; j=1; for (int i=1;;i++) { if (i%3==0 or i%5==0) a[j++]=i; if (j>100001) break; } while (scanf("%d",&n)!=EOF) cout<<a[n]<<endl; return 0; }