def main():
    S = input()

    minlen = 101
    len_ = 0
    for i in range(len(S) - 2):
        text = ''
        for j in range(i, len(S)):
            if S[j] == 'c' and text == '':
                len_ = 1
                text = 'c'
            elif S[j] == 'w':
                text = text + 'w'
            if text == 'cww':
                minlen = min(minlen, len_)
            len_ += 1

    if minlen == 101:
        print(-1)
    else:
        print(minlen)

main()