S = raw_input()
bcnt = 0
wcnt = 0
for i in range(8):
    t = tuple(raw_input().split())
    bcnt += t.count('b')
    wcnt += t.count('w')

if bcnt == wcnt:
    print S
else:
    if S == 'oda':
        print 'yukiko'
    else:
        print 'oda'