N=int(input())
C=int(input())
V=int(input())

S=list(map(lambda x:int(x)-1,input().split()))
T=list(map(lambda x:int(x)-1,input().split()))
Y=list(map(int,input().split()))
M=list(map(int,input().split()))

G=[[] for _ in range(N)]
for i in range(V):
    G[S[i]].append((T[i],Y[i],M[i]))

inf=float("inf")

DP=[[inf]*(C+1) for _ in range(N)]

DP[0][0]=0
for i in range(N-1):
    for u,m,t in G[i]:
        for j in range(C+1):
            if j+m>C:
                break
            DP[u][j+m]=min(DP[u][j+m],DP[i][j]+t)

ans=min(DP[N-1])

if ans==inf:
    print(-1)
else:
    print(ans)