#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0; i<(n); i++)
int main()
{
	string S;
	vector<string> 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 );
			i += ( pos - i );
		}
		str.push_back( tmp );
	}
	cout <<  ( str[ 0 ] < str[ 1 ] ? "NO" : "YES" ) << endl;
	return 0;
}