12 c n

for n in range(4, 10000):
    s = '5' + '2' * n
    while ('52' in s) or ('2222' in s) or ('1122' in s):
        if '52' in s:
            s = s.replace('52', '11', 1)
        if '2222' in s:
            s = s.replace('2222', '5', 1)
        if '1122' in s:
            s = s.replace('1122', '25', 1)
    if sum(map(int, s)) == 64:
        print(n)