#coding: utf-8
#yuki_001

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=float("inf")

dp=[[INF for i in xrange(c+1)] for j in xrange(n)]
dp[0][0]=0
G=[[] for i in xrange(n)]
for i in xrange(v):
 G[s[i]-1].append((t[i]-1,y[i],m[i]))
 
for i in xrange(n):
 for j in xrange(c+1):
  if dp[i][j]!=INF:
   for t,y,m in G[i]:
    if j+y<=c:
     dp[t][j+y]=min(dp[t][j+y],dp[i][j]+m)

res=min(dp[n-1])
if res==INF:
 print -1
else:
 print res