#include <bits/stdc++.h>
using namespace std;
int main()
{
	string S;
	vector<int> str;
	while( getline( cin, S, '.' ) )
	{
		istringstream ss( S );
		int a;
		while ( ss >> a )
		{
			str.push_back( a );
		}
	}
	if( str[0] < str[3] )
	{
		cout << "NO" << endl;
		return 0;
	}
	else if( str[0] == str[3] )
	{
		if( str[1] < str[4] )
		{
			cout << "NO" << endl;
			return 0;
		}
		else if( str[1] == str[4] )
		{
			if( str[2] < str[5] )
			{
				cout << "NO" << endl;
				return 0;
			}
		}
	}   
	cout << "YES" << endl;
	return 0;
}