#include <bits/stdc++.h>
#define int long long
using namespace std;
int n;
int gf(int n) {
	int l=0,r=3*n,ans;
	while(l<=r) {
		int mid=l+(r-l)/2;
		int cnt=mid-mid/3-mid/5+mid/15;
		if(cnt<n) {
			l=mid+1;
			ans=mid;

		} else {
			r=mid-1;
		}
	}
	return ans+1;
}
signed main() {
	freopen("number.in","r",stdin);
	freopen("number.out","w",stdout);
	cin>>n;
	cout<<gf(n);
	return 0;
}