import re


def count_length_cww(cww_str):
    if cww_str:
        return len(cww_str[0])
    return -1


def extract_cww(n):
    cww_str = re.findall("c.*w.*w", n)
    return cww_str


def main():
    n = input()
    cww_str = extract_cww(n)
    answer = count_length_cww(cww_str)
    print(answer)


if __name__ == "__main__":
    main()