#include <iostream>
using namespace std;

struct Player {
  string name;
  string score;
  bool operator<(const Player &other) const {
    int n1 = static_cast<int>(score.size()),
        n2 = static_cast<int>(other.score.size());
    if(n1 < n2) { return true; }
    if(n2 < n1) { return false; }
    for(int i=0; i<n1; ++i) {
      if(score[i] < other.score[i]) { return true; }
      if(other.score[i] < score[i]) { return false; }
    }
    return false; // 等しいとき
  }
};

string f(Player o1, Player o2) {
  if(o1 < o2) { return o2.name; }
  if(o2 < o1) { return o1.name; }
  return "-1";
}

int main(void) {
  string a, x, unused1, b, y, unused2;
  cin >> a >> x >> unused1 >> b >> y >> unused2;
  string res = f(Player{a, x}, Player{b, y});
  cout << res << '\n';
  return 0;
}