题解 | #最长回文子串#

while True:
    try:
        s = input()
        res = []
        opt = ''
        for i in range(len(s)):
            for j in range(i+1, len(s)+1):
                if s[i:j] == s[i:j][::-1]:
                    res.append(s[i:j])
        for i in res:
            if len(i) > len(opt):
                opt = i
        print(len(opt))
    except:
        break