import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np

S = np.frombuffer(read().rstrip(),'S1')

N = len(S)
answer = 0
# 中心が n の場合
for n in range(N):
    left = S[:n][::-1]
    right = S[n+1:]
    L = min(len(left), len(right))
    x = np.count_nonzero(left[:L] == right[:L]) * 2 + 1
    if answer < x:
        answer = x
# 中心が間の場合
for n in range(N):
    left = S[:n][::-1]
    right = S[n:]
    L = min(len(left), len(right))
    x = np.count_nonzero(left[:L] == right[:L]) * 2
    if answer < x:
        answer = x

print(answer)