Untitled

#include <iostream>
#include <string>

using namespace std;
int main()
{
	string s, x;
	cin >> s;
	s += ' ';
	int y = 0, temp = 0, temp2 = 0, null=0;
	for (auto c : s) {
		
		if (c >= '0' && c <= '9')
		{
			if (c == '0' && null == 1)
			{
				cout << "NO";
				return 0;
			}
			if (c=='0')
			{
				null++;
			}
			
			x += c;
			
			temp2++;
		}
		else if (c == '.' && temp < 3 && temp2 >= 1)
		{
			y = stoi(x);
			if (y < 0 || y>255)
			{
				cout << "NO";
				return 0;
			}
			temp2 = 0;
			temp++;
			y = 0;
			null = 0;
			x.clear();
		}
		else if (temp == 3 && c == ' ' && temp2 >= 1)
		{
			y = stoi(x);
			if (y >= 0 && y <= 255)
			{
				cout << "YES";
			}
			else
			{
				cout << "NO";
				return 0;
			}
		}
		else
		{
			cout << "NO";
			return 0;
		}

	}
	return 0;
}