#include <bits/stdc++.h>
#include <cmath>
using namespace std;
#define ll long long
const ll mmod = 998244353;
#define vl vector<long long>
#define vll vector<vector<long long>>
ll n,k;
vll dp;
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
ll n,k;
cin >> n >>k;
dp.resize(n+1, vl (k+1, -1e18));
vl in;
vl out;
for (ll i = 0; i < n; i++){ll num; cin >> num; in.push_back(num);}
for (ll i = 0; i < n; i++){ll num; cin >> num; out.push_back(num);}
for (ll i = 0; i<n; i++) dp[i][0] = 0;
for (ll i = 1; i <n+1; i++){
for (ll j = 1; j < k+1; j++){
dp[i][j] = max(dp[i-1][j] - in[i-1], dp[i-1][j-1] - in[i-1] + out[i-1]);
}
}
ll ans = -1e18;
for (ll i = 1; i < n+1; i++) ans = max(ans, dp[i][k]);
cout << ans;
return 0;
}
