input_list = input().split()

converted_list = []
for item in input_list:
    if item == "NO":
        converted_list.append(1)
    elif item == "YES":
        converted_list.append(0)
    else:          
        converted_list.append(int(item))

possible_list = list(range(0, 10))
for i in range(1, converted_list[0] + 1): 
    if converted_list[5 * i] == 0:
        possible_list = list(set(possible_list) & set(converted_list[(5 * i - 4):(5 * i)]))
    elif converted_list[5 * i] == 1:
        possible_list = list(set(possible_list) - set(converted_list[(5 * i - 4):(5 * i)]))

print(possible_list[0])