HDU 2206

/**********************************************************************
 * 巨蛋疼的题。。。
**********************************************************************/
import java.io.*;
import java.util.*;

public class Main
{
	static int INF_INT = 0x3f3f3f3f;
	static long INF_LONG = 0x7fffffffffffffffL;
	static double PI = Math.acos(-1.0);
	static double oo = 10e9;
	static double eps = 10e-9;
	
	static Scanner cin = new Scanner(new BufferedInputStream(System.in));
	
	static String str = new String("");
	static boolean isvalid()
	{
		if (str.length() > 15)
		{
			return false;
		}
		int ncnt = 0;
		for (int i = 0; i < str.length(); ++i)
		{
			if ('.' == str.charAt(i))
			{
				++ncnt;
			}
			else if (!('0' <= str.charAt(i) && str.charAt(i) <= '9'))
			{
				return false;
			}
		}
		if (ncnt != 3)
		{
			return false;
		}
		if ('.' == str.charAt(0) || '.' == str.charAt(str.length() - 1))
		{
			return false;
		}
		for (int i = 1; i < str.length(); ++i)
		{
			if ('.' == str.charAt(i - 1) && '.' == str.charAt(i))
			{
				return false;
			}
		}
		int ptr = 0;
		while (ptr < str.length())
		{
			int buf = 0;
			while (ptr < str.length())
			{
				if (str.charAt(ptr) == '.')
				{
					break ;
				}
				buf *= 10;
				buf += (int)(str.charAt(ptr) - '0');
				if (buf > 255)
				{
					return false;
				}
				++ptr;
			}
			if (ptr == str.length())
			{
				break ;
			}
			if (str.charAt(ptr) == '.')
			{
				++ptr;
			}
		}
		return true;
	}
	public static void main(String[] args)
	{
		while (cin.hasNext())
		{
			str = cin.nextLine();
			System.out.print(isvalid() ? "YES" : "NO");
			System.out.println();
		}
		return ;
	}
}