uni = {'1', '2', '3', '4', '5', '6', '7', '8', '9'}

for _ in range(int(input())):
    line = input().split()
    if line[-1] == 'YES':
        uni = uni & set(line[:-1])
    elif line[-1] == 'NO':
        uni = uni - set(line[:-1])

print(list(uni)[0])