turn = int(input())

canditate = {i for i in range(10)}

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

if canditate:
    print(list(canditate)[0])