N = int(input())
C = int(input())
V = int(input())
S = [ int(x) - 1 for x in input().split() ]
T = [ int(x) - 1 for x in input().split() ]
Y = list(map(int, input().split()))
M = list(map(int, input().split()))

dp = [ [ 10 ** 18 ] * N for i in range(C + 1) ]
dp[0][0] = 0
for i in range(1, C + 1):
	for j in range(V):
		if i >= Y[j]:
			dp[i][T[j]] = min(dp[i][T[j]], dp[i - Y[j]][S[j]] + M[j])

answer = 10 ** 18
for i in range(1, C + 1):
	answer = min(answer, dp[i][N - 1])

if answer < 10 ** 18:
	print(answer)
else:
	print(-1)