# coding: utf-8
N = int(raw_input())
C = int(raw_input())
V = int(raw_input())
S = map(int, raw_input().split())
T = map(int, raw_input().split())
Y = map(int, raw_input().split())
M = map(int, raw_input().split())

INF = 1e9+7

# dpテーブル
# dp[i][k]=i番目の街で、所持金kの時の最短経路
# 辿りつけない時はINF
dp = [[INF for _ in range(C+1)] for _ in range(N)]
for i in range(C+1):
	dp[0][i]=0

next_town = [[] for _ in range(N)]
cost = [[INF for _ in range(N)] for _ in range(N)]
time = [[INF for _ in range(N)] for _ in range(N)]

for i in range(V):
	next_town[S[i]-1].append(T[i]-1)
	cost[S[i]-1][T[i]-1] = Y[i]
	time[S[i]-1][T[i]-1] = M[i]

for i in range(N):
	for k in range(C+1):
		if dp[i][k]!=INF:
			for j in next_town[i]:
				if k + cost[i][j] <= C:
					dp[j][k+cost[i][j]]=min(dp[j][k+cost[i][j]],dp[i][k]+time[i][j])

res = INF
for i in range(C+1):
	res = min(res, dp[N-1][i])

if dp[N-1][C] == INF: print -1
else: print dp[N-1][C]