#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin() , v.end()
#define ios ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
#define int long long

using namespace std;

typedef long long LL;
typedef pair<int , int> PII;

const int N = 1e5 + 5;
const int mod = 998244353;
const int INF = 0x3f3f3f3f;
int a[N],b[N],n,k;
int dfs(int turn,int x,int y) {
    if(turn==2*n+1) return 0;
    if(turn&1) {
        int res=turn/2;
        int ret=res+x-y+1;
        int ans=-1e18;
        if(x+1<=k) ans=max(ans,dfs(turn+1,x+1,y)+a[ret]);
        ans=max(ans,dfs(turn+1,x,y));
        return ans;
    } else {
        int res=turn/2;
        int ret=res-x+y+1;
        int ans=1e18;
        if(y+1<=k) ans=min(ans,dfs(turn+1,x,y+1)-b[ret]);
        ans=min(ans,dfs(turn+1,x,y));
        return ans;
    }
}
void solve(){
    cin>>n>>k;
    for(int i=1;i<=n;i++) cin>>a[i];
    for(int i=1;i<=n;i++) cin>>b[i]; 
    sort(a+1,a+n+1);
    sort(b+1,b+n+1);
    reverse(a+1,a+n+1);
    reverse(b+1,b+n+1);
    cout<<dfs(1,0,0)<<endl;
}

signed main(){
    ios;
    int T = 1;
    // cin >> T;
    while(T --){
        solve();
    }
    return 0;
}
/*
5
1 2
2 3
2 4
1 5
*/