S = input()
L = len(S)
import re
cand = []
for i in range(L-1):
    for j in range(i+1, L+1):
        replaced = [char for char in S[i:j] if char in "cw"]
        if "cww" in "".join(replaced):
          cand += [j-i]
if cand:
  print(min(cand))
else:
  print(-1)