S = input()

def solve(S):
    n = len(S)
    record = 1
    for start in range(n):
        for end in range(start + 1, n + 1):
            word = S[start:end]
            if word == word[::-1]:
                length = end - start
                if length > record:
                    record = length
    return record

n = len(S)
s = solve(S)
if n == s:
    s = max(solve(S[1:]), solve(S[:-1]))
print(s)