public class D060WaitAMinute {
public static void main(String[] args) {
java.util.Scanner sc = new java.util.Scanner(System.in);

System.out.println(getTime(sc.nextInt()));
}

public static int getTime(int m) {
return (m == 25) ? 0 : (m > 25) ? 60-(m - 25) : 25 - m;
}
}