from collections import defaultdict

INF = 1 << 60
N, M, K = map(int, input().split())
C = list(map(lambda x: int(x)-1, input().split()))
A = list(map(int, input().split()))

d = defaultdict(int)
for i in range(K):
    d[C[i]] += 1

ans = INF
for k, v in d.items():  # (色, 個数)
    cost = A[k] * (K - v)
    ans = min(ans, cost)

for a in A:
    ans = min(ans, a * K)

for i in range(K, N):
    d[C[i]] += 1
    d[C[i-K]] -= 1

    cost = A[C[i]] * (K - d[C[i]])
    ans = min(ans, cost)

print(ans)