def recursin_operation(S, len_init_s):
    S = list(S)
    N = len(S)
    lst = [i for i in range(N - 1) if S[i] != S[i + 1]]
    nums_of_deleted = []
    if len(lst) != 0:
        for i in lst:
            S_next = [S[j] for j in range(len(S)) if j < i or j > i + 1]
            nums_of_deleted.append(recursin_operation(S_next, len_init_s))
    else:
        nums_of_deleted.append(len_init_s - len(S))

    return max(nums_of_deleted)


def main():
    S = input()
    len_init_s = len(S)
    ans = recursin_operation(S, len_init_s)
    print(ans)


if __name__ == "__main__":
    main()
