N = int(input())
num4 = [list(input().split()) for x in range(N)]
r = {i for i in range(10)}

for num in num4:
    if num[-1] == 'YES':
        r = r.intersection([int(s) for s in num[:4]])
    elif num [-1] == 'NO':
        r = r.difference([int(s) for s in num[:4]])

print(list(r)[0])