from typing import *
n = int(input())
possible = set(i + 1 for i in range(n))  # type: Set[int]
previous = ""  # type: Any
current = ""  # type: Any
while current != "HELP":
    current = input()
    if current == "YES":
        possible = possible.intersection(set(map(int, previous.split())))
    elif current == "NO":
        possible -= set((map(int, previous.split())))
    previous = current
print(*sorted(possible))