#include<bits/stdc++.h>
using namespace std;
#define int long long
void solve() {
    int n, k; cin >> n >> k;
    vector<int> a(n), b(n);
    for(int i = 0; i < n; ++ i) 
        cin >> a[i];
    for(int i = 0; i < n; ++ i) 
        cin >> b[i];
    
    sort(a.begin(), a.end(), greater<int>());
    sort(b.begin(), b.end(), greater<int>());
    
    int lim = 2 * n, up = min(k, n);
    const int INF = 0x3f3f3f3f3f3f3f3fll;
    
    vector<vector<vector<int> > > f(lim + 2, vector<vector<int> > (up + 2, vector<int>(k + 2)));
    vector<vector<vector<bool> > > vis(lim + 2, vector<vector<bool> > (up + 2, vector<bool>(k + 2)));
    
    auto dfs = [&](auto self, int i, int A, int B) -> int {
        if (i > lim) return 0;
        
        int illegal = (i & 1) ? -INF : INF, tim = ((i - 1) / 2) + ((i & 1) == 0); 
        
        if (((i & 1) && (tim - B + A) > n) || (!(i & 1) && (tim - A + B) > n)) return illegal;
        
        if (vis[i][A][B]) return f[i][A][B]; 
        vis[i][A][B] = true; 
        f[i][A][B] = illegal;
        
        if ((i & 1) && (tim - B + A) < n && A + 1 <= up) f[i][A][B] = self(self, i + 1, A + 1, B) + a[tim - B + A];
        if (!(i & 1) && (tim - A + B) < n && B + 1 <= up) f[i][A][B] = self(self, i + 1, A, B + 1) - b[tim - A + B];
        if (i & 1) return f[i][A][B] = max(f[i][A][B], self(self, i + 1, A, B));
        else return f[i][A][B] = min(f[i][A][B], self(self, i + 1, A, B));
    };
    cout << dfs(dfs, 1, 0, 0) << "\n";
    // for(int i = 1; i <= lim; ++ i)
    //     for(int A = 0; A <= up; ++ A)
    //         for(int B = 0; B <= up; ++ B) {
    //             if (!vis[i][A][B]) cerr << " --- ";
    //             cerr << "Find : " << i << " " << A << " " << B << " | " << vis[i][A][B] << " | " << f[i][A][B] << "\n";
    //         }
    return;
}
signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0), cin.tie(0);
    int T = 1;
    // cin >> T;
    while(T--) {
        solve();
    }
    return 0;
}