if __name__ == '__main__':
    yes_list = []
    no_list = []

    n = int(input())
    for _ in range(n):
        *numbers, r = input().split()
        (yes_list if r == 'YES' else no_list).extend(map(int, numbers))
    
    memo = list(range(10))
    for x in no_list: memo[x] = None

    l = len(yes_list)
    if l == 0: answer = [x for x in range(10) if memo[x] is not None]
    if l == 4: answer = [x for x in range(10) if x in yes and memo[x] is not None]
    if l >  4: answer = [x for x in range(10) if yes_list.count(x) > 1 and memo[x] is not None]

    print(answer[0])