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

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
    for(T& x : vec) is >> x;
    return is;
}

template<class T> ostream& operator << (ostream& os, const vector<T>& vec) {
    if(vec.empty()) return os;
    os << vec[0];
    for(auto it = vec.begin(); ++it != vec.end(); ) os << ' ' << *it;
    return os;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    vector<int> a(n), b(n), c(n);
    cin >> a >> b >> c;
    ll ans = accumulate(a.begin(), a.end(), 0ll);
    for(int i = 0; i < n; i++){
        ans += c[i];
        b[i] = b[i] - c[i];
    }
    sort(b.rbegin(), b.rend());
    for(int i = 0; i < k; i++){
        ans += b[i];
    }
    cout << ans << '\n';
}