N=int(input())
A=set(map(str,[0,1,2,3,4,5,6,7,8,9]))
for i in range(N):
    T=list(input().split())
    if T[4]=="NO":
        A=A - set(T[0:4])
    if T[4]=="YES":
        A=A & set(T[0:4])
print(list(A)[0])