import java.util.Scanner;

public class A {
    public static void main(String[] args) {
        for (Scanner cin = new Scanner(System.in);
             cin.hasNext();
             System.out.println(check(cin.nextLine().split("\\.")) ? "Y" : "N"))
            ;

    }

    private static boolean check(String[] ss) {
        if (ss.length != 4)
            return false;
        for (String s : ss)
            if (!check(s))
                return false;
        return true;
    }

    private static boolean check(String s) {
        int ip = 0;
        try {
            ip = Integer.parseInt(s);
        } catch (Exception e) {
            return false;
        }
        return ip <= 255 && ip >= 0;
    }
}