def find_cww_str(n):
    """
    文字列を取り出す関数
    """
    cww_str_list = []
    for i in range(len(n)):
        if n[i] == "c":
            i += 1
            for j in range(i, len(n)):
                if n[j] == "w":
                    j += 1
                    for k in range(j, len(n)):
                        if n[k] == "w":
                            cww_str_list.append(n[i - 1 : k + 1])

    return cww_str_list


def character_numbers(cww_str):
    """
    文字列を並び替えて最小値を返す関数
    """
    if cww_str == []:
        return -1
    asc_number = sorted(cww_str, key=len)
    return len(asc_number[0])


def main():
    n = input()
    cww_str = find_cww_str(n)
    result = character_numbers(cww_str)
    print(result)


if __name__ == "__main__":
    main()