
#include<bits/stdc++.h>
using namespace std;



int main(){
	//freopen("output.txt","r",stdin);

	int t;
	cin>>t;
	long int sum = 0;
	for(int i=1;i<=n;i++){
		if(i % 3 != 0 && i % 5 != 0)
			sum += i;
	}

	cout<<sum<<endl;
}