N = int(input())
S = list(input())

flag = False
countA = 0
countBtmp = 0
countB = 0
for i in range(N):
  if S[i] == '#':
    flag = True
    countBtmp = countBtmp + 1
  elif flag is True:
    countA = countA + 1
    countB = countBtmp

if countA < countB:
  print("countA")
else:
  print("countB")