import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long[] sum = new long[n+1];
		sum[1] = 1;
		for (int i = 2; i < n+1; i++) {
			if (i % 3== 0 || i%5 ==0) {
				sum[i] = sum[i-1];
			} else {
				sum[i] = sum[i-1] + i;
			}
		}
		System.out.println(sum[n]);
	}

}

/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