python

while True:
    try:
        string = str(input())
        string_reverse = string[::-1]
        length = len(string)
        substring_list = []
        for i in range(length):
            for j in range(i+1,length+1):
                substring = string[i:j]
                substring_length=len(substring)
                substring_reverse = string_reverse[length-i-substring_length:length-i]
                if substring_reverse == substring:
                    substring_list.append(substring)
        substring_list.sort(key= lambda x: len(x),reverse=True)
        print(len(substring_list[0]))
    except:
        break