class heap_queue:
    def __init__(self):
        self.queue = [(0, 0, 0)] # 時間, 駅, コスト
    
    def add(self, *item):
        self.queue.append(tuple(item))
        self.queue.sort(key=lambda x:x[0], reverse=True)
    
    def dequeue(self):
        if not self.size():
            return False
        return self.queue.pop()
    
    def size(self):
        return len(self.queue)

N = int(input())
C = int(input())
V = int(input())
S = list(map(lambda x:int(x) - 1, input().split())) # 行く前
T = list(map(lambda x:int(x) - 1, input().split())) # 行った後
Y = list(map(int, input().split())) # コスト
M = list(map(int, input().split())) # 時間

dp = [10 ** 9 for j in range(N)]
dp[0] = 0

heap = heap_queue()
while heap.size():
    data = list(heap.dequeue())
    
    for i in range(V):
        if S[i] == data[1]:
            if Y[i] + data[2] <= C:
                dp[T[i]] = min(dp[T[i]], data[0] + M[i])
                heap.add(dp[T[i]], T[i], Y[i] + data[2])

print(dp[N - 1] if dp[N - 1] != 10 ** 9 else -1)