while True:
    try:
        s=input()
        m=0
        for i in range(len(s)):
            for j in range(i+1,len(s)+1):
                if s[i:j] == s[i:j][::-1] and j-i > m:
                    m=j-i
                else:
                    continue
        if m != 0:
            print(m)
    except:
        break