#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cstdio>
using namespace std;
int main(){
    string s1,s2;
    int a1,a2;
    char none;
    cin >> s1 >> a1 >> none >> s2 >> a2 >> none;
    if(a1>a2)   cout << s1;
    else if(a1 == a2)   cout << -1;
    else    cout << s2;
    return 0;
}