s = list(input())
ans = -1

for _ in range(len(s)):
    b = s.pop(0)
    if b == 'c':
        cww = []
        wc = 0
        for i in s:
            cww.append(i)
            if i == 'w':
                wc += 1
                if wc == 2:

                    ans = [len(cww)+1, ans][0 < ans < len(cww)+1]
print(ans)