import sys,heapq
input = sys.stdin.buffer.readline
S=input()
n=len(S)
ans=1
for i in range(1,n-1):
  cur=1
  for j in range(i):
    if i+i-j<n and S[j]==S[i+i-j]:
      cur+=2
  ans=max(ans,cur)
print(ans)