def main():
    S = input()

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

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

main()