#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
    for(T& x : vec) is >> x;
    return is;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k, n2;
    cin >> n >> k;
    n2 = 2 * n;
    vector<int> a(n), c(n);
    vector<ll> sa(n2 + 1);
    cin >> a >> c;
    a.insert(a.end(), a.begin(), a.end());
    c.insert(c.end(), c.begin(), c.end());
    for(int i = 0; i < n2; i++){
        sa[i + 1] = sa[i] + a[i];
        c[i]--;
    }
    vector<vector<ll>> dp(n2 + 1, vector<ll>(n2 + 1));
    for(int i = 0; i < n2; i++) dp[i][i + 1] = 1ll << c[i];
    ll ans = *max_element(a.begin(), a.end());
    for(int len = 2; len <= n; len++){
        for(int l = 0; l + len <= n2; l++){
            int r = l + len;
            for(int m = l + 1; m < r; m++){
                dp[l][r] |= dp[l][m] & dp[m][r];
                for(int i = 1; i <= k; i++){
                    dp[l][r] |= dp[l][m] & (dp[m][r] >> k);
                    dp[l][r] |= dp[l][m] & (dp[m][r] << k);
                    dp[l][r] |= (dp[l][m] >> k) & dp[m][r];
                    dp[l][r] |= (dp[l][m] << k) & dp[m][r];
                }
            }
            if(dp[l][r]) ans = max(ans, sa[r] - sa[l]);
        }
    }
    cout << ans << '\n';
}