import heapq
N,C,V = int(input()),int(input()),int(input())
S = [int(i) - 1 for i in input().split()]
T = [int(i) - 1 for i in input().split()]
Y = [int(i) for i in input().split()]
M = [int(i) for i in input().split()]
cost = [[-1 for j in range(N)]for i in range(N)]
time = [[-1 for j in range(N)] for i in range(N)]
for i in range(V):
	cost[S[i]][T[i]] = Y[i]
for i in range(V):
	time[S[i]][T[i]] = M[i]
def dijkstra():
	q = [(0,C,0)]
	while len(q) > 0:
		d = heapq.heappop(q)
		if d[2] == N - 1 and d[1] >= 0:
			return d[0]
		for i in range(N):
			if d[2] == i or cost[d[2]][i] == -1 or time[d[2]][i] == -1:
				continue
			heapq.heappush(q,(d[0] + time[d[2]][i],d[1] - cost[d[2]][i],i))
	return -1
print(dijkstra())