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()))
dic = {}


def sum_time(t, y):
    if (t, y) in dic:
        return dic[(t, y)]

    if y < 0:
        dic[(t, y)] = float("inf")
        return dic[(t, y)]

    if t == 1:
        dic[(t, y)] = 0
        return dic[(t, y)]

    minm = float("inf")
    for i in range(V):
        if t == T[i]:
            minm = min(sum_time(S[i], y-Y[i]) + M[i], minm)
    dic[(t, y)] = minm
    return dic[(t, y)]


M = sum_time(N, C)
if float("inf") > M >= 0:
    print(M)
else:
    print(-1)