#include<bits/stdc++.h>

using namespace std;
using ll = long long;

bool is_integer(double x){
    return floor(x) == x;
}

int main(){
    string sa,sb,pa,pb,xa,xb;

    cin >> sa >> pa >> xa;
    cin >> sb >> pb >> xb;

    string winner = "";

    auto comp = [&]() -> bool {
        int na = pa.size(),nb = pb.size();

        if(na > nb){
            winner = sa;
            return true;
        }else if(na < nb){
            winner = sb;
            return true;
        }else{
            for(int i=na;i >= 0;i--){
                if(pa[i] > pb[i]) winner = sa;
                else if(pa[i] < pb[i]) winner = sb;
                else continue;
            }
            if(winner == "") return false;
            return true;
        }
    };
    cout << (comp() ? winner : "-1") << endl;
}