def intm(string):
    return int(string) - 1

# return minimum time to N
def goforward(start, curcost, curtime):
    if start == N - 1:
        return curtime
    smallest = 1e+10
    for i in range(V):
        if S[i] == start:
            nexcost = curcost + Y[i]
            nextime = curtime + M[i]
            if nexcost > C:continue
            result = goforward(T[i], nexcost, nextime)
            #print("{} -> {} :{}".format(start, T[i], result))
            smallest = min(smallest, result)

    return smallest


N = int(input())
C = int(input())
V = int(input())
S = list(map(intm, input().split(" ")))
T = list(map(intm, input().split(" ")))
Y = list(map(int, input().split(" ")))
M = list(map(int, input().split(" ")))

result = goforward(0, 0, 0)
if result >= 1e+9:
    result = -1
print(goforward(0, 0, 0))