#include<bits/stdc++.h>
using namespace std;
const int N = 2e6 + 9;
int n,m;
struct card{
	int num,id,typ;
} a[N];
bool cmp(card c1,card c2){
	return (c1.num ^ c2.num) ? c1.num < c2.num : c1.typ < c2.typ;
}
int vis[N];
int cnt;
int tot,bucket[N][2];
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	cin >> n >> m;
	for(int i = 1;i <= n;i++){
		cin >> a[i].num;
		a[i].id = i;
		a[i].typ = 1;
	}
	for(int i = 1;i <= n;i++){
		cin >> a[i + n].num;
		a[i + n].id = i;
		a[i + n].typ = 2;
	}
	n <<= 1;
	sort(a + 1,a + n + 1,cmp);
	int l = 1,r = 0;
	int ans = INT_MAX;
	while(l <= n){
		while(r < n && cnt < (n >> 1)){
			r++;
			vis[a[r].id]++;
			bucket[a[r].id][a[r].typ]++;
			if(vis[a[r].id] == 1)
				cnt++;
			if(a[r].typ == 1 && bucket[a[r].id][2])
				tot--;
			if(a[r].typ == 2 && !bucket[a[r].id][1])
				tot++;
		}
		if(cnt == (n >> 1) && tot <= m)
 			ans = min(ans,a[r].num - a[l].num);
		vis[a[l].id]--;
		if(!vis[a[l].id])
			cnt--;
		if(a[l].typ == 1 && bucket[a[l].id][2])
			tot++;
		if(a[l].typ == 2 && !bucket[a[l].id][1])
			tot--;
		bucket[a[l].id][a[l].typ]--;
		l++;
	}
	cout << ans;
	return 0;
}