2

def sol(table_sorted, n):

    Wt, Ht = table_sorted[0], table_sorted[1]
    price = float("infinity")

    for i in range(n):

        cloth = [int(i) for i in input().split()]
        Wc, Hc = min(cloth[0], cloth[1]), max(cloth[0], cloth[1])

        if Wc >= Wt and Hc >= Ht:
            price = min(price, cloth[2])

    return price


n = int(input())
print(sol(sorted(tuple([int(i) for i in input().split()])), n))