import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		scan.close();
		int min = 0;
		if(N < 100) {
			min = 4;
		}else {
			min = N - 100;
			if(min % 2 == 1) {
				min = min + 1;
			}
		}
		System.out.println(min);
	}
}