import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String[] inputs = reader.readLine().split(" ");
        String SA = inputs[0];
        BigInteger PA = new BigInteger(inputs[1]);
        inputs = reader.readLine().split(" ");
        String SB = inputs[0];
        BigInteger PB = new BigInteger(inputs[1]);
        showResult(SA,SB,PA,PB);
    }

    private static void showResult(String playerA, String playerB, BigInteger pointA, BigInteger pointB) {
        if(pointA.compareTo(pointB) == 1) {
            System.out.println(playerA);
        } else if (pointA.compareTo(pointB)==0){
            System.out.println("-1");
        } else {
            System.out.println(playerB);
        }
    }
}