#include <bits/stdc++.h> using namespace std; int main() { int i,j,n,a[100001]; i=3; j=1; while (true) { if (i%3==0 or i%5==0) a[j++]=i; i++; if (j>100000) break; } while (scanf("%d",&n)!=EOF) cout<<a[n]<<endl; return 0; }