def main():
    n = input()
    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])
                            small_cww = sorted(cww_str_list, key=len)
                        else:
                            continue
                else:
                    continue
        else:
            continue
    if cww_str_list == []:
        print(-1)
    else:
        print(len(small_cww[0]))


if __name__ == "__main__":
    main()