class MyRegex{ String pattern ="((2[0-5][0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])\.){3}(2[0-5][0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])"; }

public String pattern = String.format("^%1s\.%1s$", "((\d{1,2})|((0|1)\d{2})|(2[0-4]\d|25[0-5]))");

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import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.Scanner;

class Solution{

public static void main(String[] args){
    Scanner in = new Scanner(System.in);
    while(in.hasNext()){
        String IP = in.next();
        System.out.println(IP.matches(new MyRegex().pattern));
    }

}

} class MyRegex{ String reg = "([0-9]|[0-9][0-9]|[0|1][0-9][0-9]|2[0-5][0-5]|2[0-4][0-9])"; String pattern = reg+"."+reg+"."+reg+"."+reg; }

import java.io.; import java.util.;

public class Solution {

public static void main(String[] args) {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
   Scanner sc = new Scanner(System.in);

   while(sc.hasNext()){
        String ip = sc.nextLine();

    List<String> eachWord = new ArrayList<>(Arrays.asList(ip.split("\\.")));

    if(ip.charAt(ip.length()-1)=='.')
        eachWord.add("");


    boolean check = true;

    if(eachWord.size()==4 && eachWord.get(0).length()>0){
        for (String string : eachWord) {
            try {
                if(string.length() > 3){
                    check = false;
                    break;
                }
                int num = Integer.parseInt(string);
                if (!(num >= 0 && num <= 255)) {
                    check = false;
                    break;
                }
            } catch (NumberFormatException e) {
                check = false; // Handles cases where parsing fails (e.g., empty strings or non-numeric parts)
                break;
            }
        }
    }
    else{
        check = false;
    }

    if(check) 
        System.out.println("true");
    else
        System.out.println("false");
   }
}

}