import java.util.*;
public class Main{
public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    long N = n;
    long m = 0 ;
    for(long i=1;i<N+1;i++){
    if ((i%3)==0){}
    else if ((i%5)==0){}
    else{
    m = m+i;
    }
    }
	System.out.println(m);
    }   
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz