/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		java.util.function.Predicate<String> f = n->n.matches("(.)\\1*");
		System.out.println(f.test("444"));
		System.out.println(f.test("12"));
		System.out.println(f.test("122"));
		System.out.println(f.test("112"));
		System.out.println(f.test("1"));
	}
}