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())
yCost=[[10**5]*N for _ in xrange(N)]
mCost=[[10**5]*N for _ in xrange(N)]
for i in xrange(V):
  yCost[S[i]-1][T[i]-1] = Y[i]
  mCost[S[i]-1][T[i]-1] = M[i]
dp=[[10**9]*(C+1) for _ in xrange(N)]
dp[0][C]=0
for _ in xrange(N):
  for i in xrange(V):
    for j in xrange(C+1):
      if j+Y[i]>C: continue
      dp[T[i]-1][j] = min(dp[T[i]-1][j], dp[S[i]-1][j+Y[i]]+M[i])
ans = 10**9
for i in xrange(C+1):
  ans = min(ans, dp[N-1][i])
if ans==10**9: print -1
else: print ans