S = input()
len_S = len(S)
ans = 0
for m in range(len_S * 2):
    tmp = 0
    for lft, rgt in zip(range(m // 2, -len_S, -1), range(m - m // 2, len_S)):
        if lft < 0 or rgt >= len_S:
            break
        if S[lft] == S[rgt]:
            tmp += 2 - (lft == rgt)
    ans = max(ans, tmp)
print(ans)