#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, k; cin >> n >> k;
  ll ans = 0;
  REP(_, n) {
    int a; cin >> a;
    ans += a;
  }
  vector<int> b(n), c(n);
  for (int& b_i : b) cin >> b_i;
  for (int& c_i : c) cin >> c_i;
  for (const int c_i : c) ans += c_i;
  REP(i, n) b[i] -= c[i];
  ranges::sort(b, greater<int>());
  ans += reduce(b.begin(), next(b.begin(), k), 0LL);
  cout << ans << '\n';
  return 0;
}