import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

S = readline().rstrip().decode()
board = read()

b = board.count(b'b')
w = board.count(b'w')

if (b+w) & 1:
    if S == 'oda':
        S = 'yukiko'
    else:
        S = 'oda'

print(S)