import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd
s = list(input().rstrip())
n = len(s)
dr = [[] for i in range(n)]
for i in range(n):
  l, r= i,i
  for j in range(n):
    ll = l-j
    rr = r+j
    if ll < 0 or rr >= n: break
    if s[ll] == s[rr]:
      dr[rr].append(ll)
    else:
      break

for i in range(n-1):
  l, r = i, i+1
  for j in range(n):
    ll = l-j
    rr = r+j
    if ll < 0 or rr >= n: break
    if s[ll] == s[rr]:
      dr[rr].append(ll)
    else:
      break

dp = [1]*(n)
for i in range(1, n):
  for j in dr[i]:
    if j == 0:
      dp[i] = i+1
    else:
      dp[i] = max(dp[i],min(i-j+1, dp[j-1]))
print(dp[-1])