S = list(input())
N = len(S)
inf = 10 ** 18
dp = [inf] * (N + 1)
for i in range(1, N + 1):
    L = []
    val = 0
    for j in range(i):
        L.append(S[i - j - 1])
        if L == L[::-1]:
            val = max(val, min(dp[i - j - 1], j + 1))
    dp[i] = val
print(dp[-1])