题解 | #密码截取#

def decoder(A):
    # write code here
    ret = 1
    size = len(A) - 1
    for i in range(1, size):
        cleft = i - 1
        cright = i + 1
        while (cleft >= 0 and A[cleft] == A[i]):
            cleft -= 1
        while (cright <= size and A[cright] == A[i]):
            cright += 1
        while (cleft>=0 and cright <= size and A[cleft] == A[cright]):
            cleft -= 1
            cright += 1
        ret = max(cright - cleft - 1, ret)
    return ret
while True:
    try:
        s = input()
    except EOFError:
        break
    print(decoder(s))