inputed_list = list(input())

res = 1
tmp_list = []
for i in range(len(inputed_list)):
    tmp_list.clear()
    for e in inputed_list:
        tmp_list.append(e)
    j = 1
    length = 1
    limit = 0
    if i < len(inputed_list) // 2:
        limit = i
    else:
        limit = len(inputed_list) - i
    for k in range(limit):
        try:
            b = tmp_list[i - j]
            f = tmp_list[i + j]
            if b == f or (b == 'b' and f == 'd') or (b == 'd' and f == 'b') or (
                            b == 'p' and f == 'q') or (b == 'q' and f == 'p'):
                length += 1
                res = max(res, length)
                j += 1
            else:
                tmp_list[i - j] = ' '
                tmp_list[i + j] = ' '
                j += 1
        except:
            break

if res == 1:
    print(0)
else:
    print(res * 2 - 1)