N, M, K = map(int, input().split())
C = list(map(int, input().split()))
A = list(map(int, input().split()))
ans = min(A) * K
cnt = [0] * (M + 1)
for i in range(N):
    cnt[C[i]] += 1
    if i >= K:
        cnt[C[i-K]] -= 1
    ans = min(ans, (K - cnt[C[i]]) * A[C[i] - 1])

print(ans)