S = input().strip()
def check(s):
    n = len(s)
    for i in range(n):
        if s[i] != s[n-i-1]:
            return False
    return True

r = 0 
N = len(S)
#print(S)
for i in range(N):
    for j in range(i+1, N+1):
        if check(S[i:j]) and j-i != N:
            r = max(r, j-i)
print(r)