import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextInt();
        long sum = 0;
        for(int i=1;i<=N;i++)
        {
            if(i%3!=0) sum = sum + i;
            if(i%5!=0) sum = sum + i;
            if(i%15!=0) sum = sum - i;
            
        }
        System.out.println(sum);
    }
}

/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