import java.util.*;

public class Main {
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	int ans = 0;
    	for (int i = 0; i * 5 <= n; i++) {
    	    for (int j = 0; j <= i && i * 5 + j * 2 <= n; j++) {
    	        if ((n - i * 5 - j * 2) % 3 == 0) {
    	            ans++;
    	        }
    	    }
    	}
    	System.out.println(ans);
	}
}