def f(L):
    N = len(L)
    temp = [None] * N
    for i in range(N):
        temp[i] = L[N - 1 - i]
    return L == temp

S = list(input())
M = len(S)
ans = 1
for i in range(M):
    for j in range(i + 1, M):
        if j - i == M - 1:
            continue
        if f(S[i:j+1]):
            ans = max(ans, j + 1 - i)
print(ans)