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

string s1, s2, p1, p2, s;
void input() { cin >> p1 >> s1 >> s >> p2 >> s2 >> s; }
void solve() {
  string ans = "-1";
  if (s1.size() > s2.size())
    ans = p1;
  else if (s1.size() < s2.size())
    ans = p2;
  else if (s1 > s2)
    ans = p1;
  else if (s1 < s2)
    ans = p2;
  cout << ans << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  input();
  solve();
}