fn main() {
    input!{
		n: usize, k: usize,
		a: [i64; n],
		b: [i64; n],
		c: [i64; n],
	}

	let mut prefer_b = vec![(0, 0); n];
	for i in 0..n {
		prefer_b[i] = (b[i]-c[i], i);
	}
	prefer_b.sort();
	prefer_b.reverse();

	let mut ans = 0;
	for i in 0..n {
		let pos = prefer_b[i].1;
		if i < k {
			ans += a[pos] + b[pos];
		}
		else {
			ans += a[pos] + c[pos];
		}
	}
	println!("{}", ans);
}

// const MOD17: usize = 1000000007;
// const MOD93: usize = 998244353;
// const INF: usize = 1 << 60;
// let dx = vec![!0, 0, 1, 0]; // 上左下右
// let dy = vec![0, !0, 0, 1]; // 上左下右
// let d = vec!{(!0, 0), (0, !0), (1, 0), (0, 1)}; // 上左下右

#[allow(unused)]
use proconio::{input, marker::Chars, marker::Usize1};

#[allow(unused)]
use std::{
	mem::swap,
	cmp::min, cmp::max,
	cmp::Reverse,
	collections::HashSet, collections::BTreeSet,
	collections::HashMap, collections::BTreeMap,
	collections::BinaryHeap,
	collections::VecDeque,
	iter::FromIterator,
};