turn = list(map(int, input().split()))[0]

canditate_no = {i for i in range(10)}
canditate_yes = {i for i in range(10)}

for i in range(turn):
 
    ans = input().split()
    ans_1 = set(map(int, ans[0:-1]))
    ans_2 = ans[-1]
    
    if ans_2 == "NO":
        canditate_no -= ans_1
    else:
        canditate_yes = canditate_yes & ans_1

if len(canditate_yes) == 1:
    print(list(canditate_yes)[0])
elif len(canditate_no) == 1:
    print(list(canditate_no)[0])
else:
    ans = canditate_no & canditate_yes
    print(list(ans)[0])