s = list(input())

def f(s):
    n = len(s)
    rs = [None for _ in range(n)]
    for i in range(n):
        rs[i] = s[n - i - 1]
    return s == rs
ans = 1
n = len(s)
for i in range(n):
    for j in range(i + 1, n):
        if j - i == n - 1:
            continue
        if f(s[i:j + 1]):
            ans = max(ans, j - i + 1)
print(ans)