N = int(input())
A = []#数値
B = []

C = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
C = set(C)
for i in range(N):
    turn = input().split()
    if turn[-1] == "Yes":
        A.append(turn[:-1])
    else:
        B.append(turn[:-1])

A_s = set(sum(A, []))
B_s = set(sum(B, []))

candidate = A_s - B_s 

A_2 = list(map(set,A))

if len(A) >= 2:
    D = A_2[0] & A_2[1]
    for i in range(len(A) - 2):
        D = D & A_2[i+2]
    print(D & candidate)

elif len(A) == 1:
    print (candidate)

else :
    print (C - B_s)