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()]
edge = [[] for i in range(N)]
for i in range(V):
	edge[S[i]].append((T[i],Y[i],M[i]))
INF = 10 ** 9 + 7
dp = [[INF for j in range(C + 1)] for i in range(N)]
dp[0][0] = 0
for i in range(N):
	for j in range(C):
		if dp[i][j] != INF:
			for e in edge[i]:
				if j + e[1] <= C:
					dp[e[0]][j + e[1]] = min(dp[e[0]][j + e[1]],dp[i][j] + e[2])
ans = min(INF,min(dp[N - 1]))
print(-1 if ans == INF else ans)