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

int main() {
  vector<string> ans(2);
  cin >> ans.at(0);
  ans.at(1) = (ans.at(0) == "oda") ? "yukiko" : "oda";
  int cnt = 0;
  char c;
  while (cin >> c) if (c == 'w' || c == 'b') cnt++;
  cout << ans.at(cnt % 2) << "\n";
}