import re

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

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

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