import java.util.Scanner;

public class Main{

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNextLine()){
            String ip = sc.nextLine();
            String[] ipSplit = ip.split("\\.");
            int i = 0;
            for (String s : ipSplit) {
                int tmp = Integer.parseInt(s);
                if(tmp<0 || tmp>255){
                    System.out.println("NO");
                    break;
                }
                i++;
            }
            if(i == ipSplit.length){
                System.out.println("YES");
            }
        }
    }
}