def func(x):
for i in range(len(x),0,-1):
for j in range(len(x)-i+1):
if i % 2 == 0 and x[j:int(j+i/2)][::-1]==x[int(j+i/2):j+i]:
return i
if i % 2 != 0 and x[j:int(j+(i-1)/2)][::-1]==x[int(j+(i-1)/2+1):j+i]:
return i
a = input()
b = func(a)
print(b)