N = int(input())

ans = []

for i in range(10):
    ans.append(i)

for i in range(N):
    turn = input().split()
    if turn[4] == "YES":
        turn.remove("YES")
        turn = [int(x) for x in turn]
        if len(ans) > 4:
            ans = turn
        else:
            ans = set(ans) & set(turn)
    else:
        turn.remove("NO")
        turn = [int(x) for x in turn]
        ans = set(ans) - set(turn)
        
ans = list(ans)
print(ans[0])