S = list(input())
N = len(S)

ok = [[False] * N for _ in range(N)]
for i in range(N):
    l = r = i
    while l >= 0 and r < N and S[l] == S[r]:
        ok[l][r] = True
        l -= 1
        r += 1

    l = i
    r = i + 1
    while l >= 0 and r < N and S[l] == S[r]:
        ok[l][r] = True
        l -= 1
        r += 1

INF = 10**9
dp = [0] * (N + 1)
dp[0] = INF

for i in range(1, N + 1):
    for j in range(i):
        if ok[j][i - 1]:
            dp[i] = max(dp[i], min(dp[j], i - j))

print(dp[N])