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

int main()
{
int i;
int iLenA;
int iLenB;
char lpNameA[ 110 ];
char lpNameB[ 110 ];
char S[ 110 ];
char A[ 10100 ];
char B[ 10100 ];

	cin >> lpNameA;
	cin >> A;
	cin >> S;
	cin >> lpNameB;
	cin >> B;

	iLenA = strlen( A );
	iLenB = strlen( B );
	do
	{
		if( iLenA > iLenB )
			cout << lpNameA << endl;
		else if( iLenA < iLenB )
			cout << lpNameB << endl;
		else
			break;
	}
	while( false );

	i = strcmp( A, B );
	if( i > 0 )
		cout << lpNameA << endl;
	else if( i < 0 )
		cout << lpNameB << endl;
	else
		cout << - 1 << endl;

	return 0;
}