n = int(input())
turn_list = []
nums_dict = {}
meta_turn_list = []

for h in range(0, 10):
    nums_dict[h] = 0

for i in range(1, n + 1):
    turn_list = input().split(" ")
    if turn_list[4] == "NO":
        meta_turn_list.append(turn_list)
    elif turn_list[4] == "YES":
        meta_turn_list.insert(0, turn_list)


for turn_list in meta_turn_list:
    *nums, ans = turn_list
    nums = [int(x) for x in nums]
    if ans == "YES":
        for j in nums:
            if j in nums_dict:
                if nums_dict[j] == "potential":
                    nums_dict[j] = "high-potential"
            else:
                nums_dict[j] = "potential"
    elif ans == "NO":
        for j in nums:
            nums_dict[j] = "non-potential"

for k in nums_dict:
    if nums_dict[k] == "high-potential":
        output = k
        break


if "output" not in locals():
    for l in range(0, 10):
        if nums_dict[l] == 0:
            output = l
            break

#print(meta_turn_list)
#print(nums_dict)
print(output)