#include <bits/stdc++.h>
using namespace std;

int Len( const char *A )
{
int i;
	
	i = 0;
	while( A[ i ] != '.' && A[ i ] != '\0' ) i++;

	return i;
}

int Chk( const char *A, const char *B )
{
int i;
int iA;
int iB;

	iA = Len( A );
	iB = Len( B );
	if( iA < iB )
	{
		cout << "NO" << endl;

		return - 1;
	}
	else if( iA > iB )
	{
		cout << "YES" << endl;

		return - 1;
	}

	for( i = 0; i < iA; i++ )
	{
		if( A[ i ] == B[ i ] )
			continue;
		else if( A[ i ] < B[ i ] )
		{
			cout << "NO" << endl;

			return - 1;
		}
		else
		{
			cout << "YES" << endl;

			return - 1;
		}
	}

	return iA;
}

int main()
{
int iPos;
int iLen;
char S[ 50 ];
char T[ 50 ];

	cin >> S;
	cin >> T;

	iPos = 0;
	do
	{
		iLen = Chk( S + iPos, T + iPos );
		if( iLen < 0 ) break;

		iPos += iLen + 1;

		iLen = Chk( S + iPos, T + iPos );
		if( iLen < 0 ) break;

		iPos += iLen + 1;

		iLen = Chk( S + iPos, T + iPos );
		if( iLen < 0 ) break;

		cout << "YES" << endl;

		return 0;
	}
	while( false );

	return 0;
}