#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
using namespace std;

#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
#define SQR(X) ((X)*(X))

typedef long long ll;
typedef unsigned long long ull;
typedef long double lb;
/* ここからが本編 */

int main(void)
{
   int i,j;
   int k;
   char s[13];
   char a;
   int cnt = 0;
   cin >> s;
   while(cin >> a) {
      if(a == 'b' || a == 'w') cnt++;
   }
   if(strcmp(s,"oda") == 0 ^ cnt % 2 == 1)
      cout << "oda" << endl;
   else cout << "yukiko" << endl;
   return 0;
}