def addr_to_int(addr):
    octet = [int(x) for x in addr.split('.')]
    a = octet[0] << 24
    b = octet[1] << 16
    c = octet[2] << 8
    d = octet[3]
    return a + b + c + d


subnet, subnet_mask_num = input().split('/')
subnet = addr_to_int(subnet)
subnet_mask_num = int(subnet_mask_num)
subnet_mask = 0xFFFFFFFF << (32 - subnet_mask_num)


N = int(input())
addresses = []
for i in range(N):
    addresses.append(addr_to_int(input()))


first_addr = subnet & subnet_mask
all_addr = 2 ** (32 - subnet_mask_num)
broadcast = first_addr + all_addr - 1


occupied = 0
for addr in addresses:
    if addr == first_addr or addr == broadcast:
        print(-1)
        exit(0)

    if addr >= first_addr and addr <= broadcast:
        occupied += 1

print(all_addr - occupied - 2)