/*Code by Leo2011*/
#include <bits/stdc++.h>

#define INF 0x3f3f3f3f
#define EPS 1e-8
#define FOR(i, l, r) for (ll(i) = (l); (i) <= (r); ++(i))
#define log printf
#define IOS                      \
	ios::sync_with_stdio(false); \
	cin.tie(nullptr);            \
	cout.tie(nullptr);

using namespace std;

typedef long long ll;

const ll N = 510;
ll m, n, a[N], b[N], l[N], r[N], dp[N][N], ans = -1;

template <typename T>

inline T read() {
	T sum = 0, fl = 1;
	char ch = getchar();
	for (; !isdigit(ch); ch = getchar())
		if (ch == '-') fl = -1;
	for (; isdigit(ch); ch = getchar()) sum = sum * 10 + ch - '0';
	return sum * fl;
}

template <typename T>

inline void write(T x) {
	static T sta[35];
	int top = 0;
	do {
		sta[top++] = x % 10, x /= 10;
	} while (x);
	while (top) putchar(sta[--top] + 48);
}

ll dfs(ll k, ll c) {
	if (c == m) return 0LL;
	if (dp[k][c] != -1) return dp[k][c];
	ll p = -INF;
	FOR(i, a[k] + 1LL, n) if(l[i] > r[a[k]]) p = max(p, dfs(r[i], c + 1LL) + b[i]);
	return dp[k][c] = p;
}

int main() {
	memset(dp, -1LL, sizeof(dp));
	n = read<ll>(), m = read<ll>();
	FOR(i, 1LL, n)
	a[i] = read<ll>();
	FOR(i, 1LL, n)
	b[i] = read<ll>();
	FOR (i, 1LL, n) {
		if (!l[a[i]]) l[a[i]] = i;
		r[a[i]] = max(r[a[i]], i);
	}
	ans = dfs(0, 0);
	if (ans < 0) {write<ll>(-1);putchar('\n');}
	else write<ll>(ans);
	return 0;
}

WA 在#10、#12、#19，都是输出-1的点，咋整啊