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 = [[0 for j in range(N)] for i in range(N)]
time = [[0 for j in range(N)] for i in range(N)] 
connect = [[False for j in range(N)] for i in range(N)]
for i in range(V):
	connect[S[i]][T[i]] = True
	cost[S[i]][T[i]] = Y[i]
	time[S[i]][T[i]] = M[i]
def dijkstra(s,t):
	q = [(0,0,s)]
	ret = 10 ** 9 + 7
	while len(q) > 0:
		d = heapq.heappop(q)
		if d[1] > C:
			continue
		if d[2] == t:
			ret = min(ret,d[0])
			continue
		for i in range(V):
			if S[i] == d[2]:
				heapq.heappush(q,(d[0] + M[i],d[1] + Y[i],T[i]))
	return -1 if ret == 10 ** 9 + 7 else ret
print(dijkstra(0,N - 1))