#define _USE_MATH_DEFINES	//M_PI(π),M_SQRT2(√2)
#include <iostream>			//std::cout, std::cin
#include <string>			//std::string
#include <vector>			//std::vector
#include <valarray>			//std::valarray
#include <algorithm>		//std::sort
#include <time.h>			//localtime_s
#include <cstdlib>			//abs
#include <cmath>			//abs,std::pow,sqrt,sin,cos,round,floor,ceil
#include <fstream>			//std::ifstream
#include <iomanip>			//std::setprecision,std::setw,std::setfill
#include <random>			//std::random(C++11)
#include <numeric>			//std::accumulate

int main(void) {

	//test用
	//std::ifstream in("test.txt");
	//std::cin.rdbuf(in.rdbuf());

	//const unsigned int MODULO = 1000000007;	//MODULO 10^9+7用

	std::string SA, SB, PA, PB, XA, XB, win;
	std::cin >> SA >> PA >> XA >> SB >> PB >> XB;

	if (PA.length() > PB.length()) {
		win = SA;
	}
	else if (PA.length() < PB.length()) {
		win = SB;
	}
	else {
		int i = 0;
		while (i < PA.length() && PA[i] == PB[i]) {
			i++;
		}
		if (PA[i] > PB[i]) {
			win = SA;
		}
		else if (PA[i] < PB[i]) {
			win = SB;
		}
		else {
			win = "-1";
		}
	}

	std::cout << win << std::endl;
}