S = input()
count_len = 0
count_cww = 0
cww_num   = -1
for i in S:
    if count_cww == 3:
        cww_num = count_len
        break
    if count_cww >= 1:
        if i == "w":
            count_cww += 1
            count_len += 1
            continue
    if i == "c":
            count_cww += 1
            count_len += 1
print(cww_num)