#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0; i<(n); i++)
int main()
{
	string S;
	vector<int> str;
	while( getline( cin, S ) )
	{
		S = S + '.';
		size_t pos = 0;
		string tmp;
		for( size_t i = pos; i < S.size(); i++ )
		{
			pos = S.find_first_of( '.' , i );
			tmp = S.substr( i, pos - i );
			str.push_back( stoi( tmp ) );
			i += ( pos - i );
		}
	}
	REP( i, 3 ){
		if( str[ i ] != str[ i + 3 ] )
		{
			if( str[ i ] <= str[ i + 3 ] )
			{
				cout << "NO" << endl;
				return 0;
			}
		}
	}
	cout << "YES" << endl;
	return 0;
}