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

#define int long long  

signed main() {  
    ios::sync_with_stdio(false);
    cin.tie(nullptr);  

	int n, k;
	cin >> n >> k;

	vector<int> a(n + 1), b(n + 1);
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	for (int i = 1; i <= n; i++) {
		cin >> b[i];
	}
	
	sort(a.begin() + 1, a.end(), greater<>());
	sort(b.begin() + 1, b.end(), greater<>());

	function<int(int, int, int)> dfs = [&](int r, int x, int y) {
		if (r == 2 * n) {
			return 0LL;
		}
		if (r % 2 == 0) {
			int mx = dfs(r + 1, x, y);
			if (x < min(k, n) && x + (r + 1) / 2 - y < n) {
				mx = max(mx, dfs(r + 1, x + 1, y) + a[x + (r + 1) / 2 - y + 1]);
			} 
			// cerr << r << " " << x << " " << y << " " << mx << "\n";
			return mx;
		} else {
			int mn = dfs(r + 1, x, y);
			if (y < min(k, n) && y + (r + 1) / 2 - x < n) {
				mn = min(mn, dfs(r + 1, x, y + 1) - b[y + (r + 1) / 2 - x + 1]);
			}
			// cerr << r << " " << x << " " << y << " " << mn << "\n";
			return mn;
		}
		assert(false);
	};

	cout << dfs(0, 0, 0) << "\n";

    return 0;
}