#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main()
{
	string s;
	getline(cin, s);
	vector <int> a(0);
	a.push_back(-1);
	int position = 0;
	if (s.find('.') == -1){
		cout << "NO";
		return 0;
	}
	for (auto c : s){
		if ((c < '0' || c > '9') && c!='.'){
			cout << "NO";
			return 0;
		}
		if (c == '.'){
			a.push_back(position);
		}
		position++;
	}
	a.push_back(s.size());
	if (a.size() != 5){
		cout << "NO";
		return 0;
	}
	for (int i = 1; i < a.size(); i++){
		if ((a[i] - a[i - 1] == 1) || (a[i] - a[i - 1] >= 5)){
			cout << "NO";
			return 0;
		}
		else if ((a[i] - a[i - 1] - 1) == 3){
			if (s[a[i - 1] + 1]>'2'){
				cout << "NO";
				return 0;
			}
			if ((s[a[i - 1] + 1] == '2') && (s[a[i - 1] + 2] > '5')){
				cout << "NO";
				return 0;
			}
			if ((s[a[i - 1] + 1] == '2') && (s[a[i - 1] + 2] == '5') && (s[a[i - 1] + 3] > '5')){
				cout << "NO";
				return 0;
			}
		}
	}
	cout << "YES";
	return 0;
}