//#include <sstream>
//#include <fstream>
//#include <deque>
//#include <queue>
//#include <stack>
//#include <set>
//#include <list>
//#include <map>
//#include <unordered_map>
//#include <functional>
//#include <utility>
//#include <bitset>
//#include <cstdlib>
//#include <ctime>
//#include <cstdio>


#include <stdlib.h>
#include <iostream>
//#include <chrono> //clock
#include <vector>
#include <string>
//#include <iomanip>  //setprecision function
//#include <cmath>	//math
//#include <cstdio>
//#include <vector>	//vector array
//#include <algorithm>	//STL algorithm
//#include <set> //STL library set
//#include <sstream> // for stringstream


using namespace std;
//using namespace std::chrono; 




int main() {
	//stringstream ss;
	//ss<<"akhil";
	//cout<<ss.str()<<endl;
	//cout<<setprecision(16);
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	
	 // TESTCASE KO DEKH KA BHAUT SARA CONDITION GENERATE MAT KRO 
	 // PAPER PD CONFIRM HO JAO THORA JADA TIME HI KYU NA LGA
	
	int N;
	cin>>N;
	int sum=0;
	for(int i=1;i<=N;i++){
		if(i%3!=0 and i%5!=0) sum+=i;
	}
 
	cout<<sum<<endl;
	
 
	return 0;
}



























