def rolling_hash(s: str):
    """[l, r] のハッシュを返す関数を返す"""
    mod = 998244353
    p = 1009
    n = len(s)
    t = [ord(c) for c in s]
    a = [0] * n
    b = [0] * n
    a[0] = t[0]
    b[0] = 1
    for i in range(1, n):
        a[i] = (a[i-1] * p + t[i]) % mod
        b[i] = (p * b[i-1]) % mod

    # [l, r] のハッシュ値
    def f(l: int, r: int) -> int:
        assert 0 <= l <= r < n
        h = a[r]
        if l > 0:
            h -= a[l-1] * b[r-l+1]
            h %= mod
        return h

    return f


class PalindromeRH:
    def __init__(self, s: str):
        self.n = len(s)
        self.h = rolling_hash(s)
        self.rh = rolling_hash(s[::-1])

    def query(self, l: int, r: int) -> bool:
        """区間 [l, r] が回文か"""
        n = self.n
        return self.h(l, r) == self.rh(n-r-1, n-l-1)


S = input()
n = len(S)

pal = PalindromeRH(S)
dp = [-1] * n
dp[0] = 1
for i in range(n):
    if pal.query(0, i):
        dp[i] = i+1

    for j in range(i):
        if dp[j] == -1: continue

        if pal.query(j+1, i):
            w = i - (j+1) + 1
            dp[i] = max(dp[i], min(w, dp[j]))

ans = dp[n-1]
print(ans)