#include <bits/stdc++.h>
using namespace std;
struct Edge {
  int from, to, capacity;
  long long cost;
};
vector<vector<int>> adj, capacity;
vector<vector<long long>> cost;
const long long INF = 1e18;
void shortest_paths(int n, int v0, vector<long long>& d, vector<int>& p) {
  d.assign(n, INF);
  d[v0] = 0;
  vector<bool> inq(n, false);
  queue<int> q;
  q.push(v0);
  p.assign(n, -1);
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    inq[u] = false;
    for (int v : adj[u]) {
      if (capacity[u][v] > 0 && d[v] > d[u] + cost[u][v]) {
        d[v] = d[u] + cost[u][v];
        p[v] = u;
        if (!inq[v]) {
          inq[v] = true;
          q.push(v);
        }
      }
    }
  }
}
long long min_cost_flow(int N, vector<Edge>& edges, int K, int s, int t) {
  adj.assign(N, vector<int>());
  cost.assign(N, vector<long long>(N, 0LL));
  capacity.assign(N, vector<int>(N, 0));
  for (Edge e : edges) {
    adj[e.from].push_back(e.to);
    adj[e.to].push_back(e.from);
    cost[e.from][e.to] = e.cost;
    cost[e.to][e.from] = -e.cost;
    capacity[e.from][e.to] = e.capacity;
  }
  int flow = 0;
  long long cost = 0;
  vector<long long> d;
  vector<int> p;
  while (flow < K) {
    shortest_paths(N, s, d, p);
    if (d[t] == INF) break;
    int f = K - flow;
    int cur = t;
    while (cur != s) {
      f = min(f, capacity[p[cur]][cur]);
      cur = p[cur];
    }
    flow += f;
    cost += f * d[t];
    cur = t;
    while (cur != s) {
      capacity[p[cur]][cur] -= f;
      capacity[cur][p[cur]] += f;
      cur = p[cur];
    }
  }
  if (flow < K)
    return -1;
  else
    return cost;
}
signed main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  ;
  int n, k;
  cin >> n >> k;
  int src = 0;
  int dest = 2 * n + 1;
  vector<Edge> e;
  for (int i = 1; i <= n; i++) {
    long long x;
    cin >> x;
    Edge xx = {src, i, 1, x};
    e.push_back(xx);
    xx = {i, i + 1, k, 0};
    if (i != n) e.push_back(xx);
  }
  for (int i = 1; i <= n; i++) {
    long long x;
    cin >> x;
    Edge xx = {i, dest, 1, x};
    e.push_back(xx);
  }
  cout << min_cost_flow(2 * n + 2, e, k, src, dest);
}
