import heapq

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()))

E=[[] for i in range(N+1)]

for i in range(V):
    E[S[i]].append((T[i],Y[i],M[i]))
    E[T[i]].append((S[i],Y[i],M[i]))

DP=[[1<<30]*(C+1) for i in range(N+1)]

DP[1][C]=0

Q=[(0,1,C)]

while Q:
    now,town,money=heapq.heappop(Q)
    if now>DP[town][money]:
        continue

    for to,y,m in E[town]:
        if money-y>=0 and DP[to][money-y]>now+m:
            DP[to][money-y]=now+m
            heapq.heappush(Q,(now+m,to,money-y))

MIN=min(DP[N])

if MIN==1<<30:
    print(-1)
else:
    print(MIN)