import re

S = input()
k = 100000000000000000000
l = list(S)
l1 = []


for i in range(len(l)):
    if l[i] == "c":
        matchOB = re.match("[c]+[^c]*[^w]*[w]+[^w]*[w]",S[i:])
    if matchOB:
        l1.append(len(matchOB.group()))

if len(l1) > 0:
    print(min(l1))
else:
    print("-1")