INF=10**10
N=int(input())
C=int(input())
V=int(input())
S=list(map(int,input().split()))
T=list(map(int,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]-1].append([T[i]-1,Y[i],M[i]])
    g[T[i]-1].append([S[i]-1,Y[i],M[i]])

from heapq import heappop, heappush, heapify
heap=[(0,C,0)]
heapify(heap)
dp=[[INF for _ in range(C+1)] for _ in range(N)]
while heap:
    mm,cc,u = heappop(heap)
    dp[u][cc]=mm
    for v,y,m in g[u]:
        if cc-y<0:continue
        if dp[v][cc-y]>mm+m:
            heappush(heap,(mm+m,cc-y,v))
print(-1 if min(dp[N-1])==INF else min(dp[N-1]))