#!/usr/bin/python
inf = float('inf')
N = int(raw_input())
C = int(raw_input())
V = int(raw_input())
S = map(lambda x: int(x)-1, raw_input().split())
T = map(lambda x: int(x)-1, raw_input().split())
Y = map(int, raw_input().split())
M = map(int, raw_input().split())
route = [[] for _ in xrange(N)]
for i in xrange(V):
    route[S[i]].append((T[i], Y[i], M[i]))
dp = [[inf for _ in xrange(C+1)] for _ in xrange(N)]
dp[0][0] = 0
for v in xrange(N):
    for c in xrange(C+1):
        for to, cost, time in route[v]:
            ncost = cost + c
            if ncost > C:
                continue
            dp[to][ncost] = min(dp[to][ncost], dp[v][c] + time)
res = min(dp[N-1])
if res == inf:
    res = -1
print res