import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = sc.nextInt();
        long s = 0;
        long s2 = 0;
        for (int a=0; a<=A; a++) {
        	if(a % 3 == 0 || a % 5 == 0){
        		s2 = a + s2;
        	}
        	else {
        		s = a + s;
        	}
        }
        System.out.println(s);
    }
}
/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