#include <iostream> using namespace std; int main(){ int n; int a[100005]; int c=0; int t=0,f=0; int bn; int flag; for(int i =1;c<100000;++i){ if(i%3==0||i%5==0){ a[c++] = i; } } while(cin>>n){ cout<<a[n-1]<<"\n"; } }