#include <stdio.h>
#include <string.h>
#include <stdlib.h>

using namespace std;

//遅刻　namaega184

int main(){
	
	char str[2][11]={"oda","yukiko"},s[11];scanf("%s",s);
	int first=(bool)strcmp(s,"oda");
	
	char c,a=0;
	for(int i=0;(c=getchar())!=EOF;i++)if(c=='w'||c=='b')a++;
	printf("%s\n",str[(a+first)%2]); 
	return 0;
}