#include<iostream>
#include<cstdio>
#include<algorithm>
#define min(a,b) a<b?a:b
using namespace std;
const int N=1000010;
struct node
{
	int id,f,val;
}s[2*N];
int n,m;
bool vis[2*N];
char ch;
bool cmp1(node a,node b)
{
	return a.val<b.val;
}
inline void read(int &x){x=0;ch=getchar();while(ch<48||ch>57)ch=getchar();while(ch>47&&ch<58)x=(x<<3)+(x<<1)+(ch^48),ch=getchar();}
int main()
{
	freopen("haoi2021_card.in","r",stdin);
	freopen("haoi2021_card.out","w",stdout);
	read(n),read(m);
	for(int i=1;i<=n;++i) read(s[i].val),s[i].id=i,s[i].f=1;
	for(int i=1;i<=n;++i) read(s[i+n].val),s[i+n].id=i;
	sort(s+1,s+2*n+1,cmp1);
	int l=0,r=2*n+1,cnt=0;
	long long ans=10000000000;
	while(!vis[s[l+1].id]&&cnt+s[l+1].f<=m) cnt+=s[l+1].f,vis[s[l+1].id]=1,++l;
	while(!vis[s[r-1].id]&&cnt+s[r-1].f<=m) cnt+=s[r-1].f,vis[s[r-1].id]=1,--r;
	while(l>=0)
	{
		ans=min(ans,s[r-1].val-s[l+1].val);
		vis[s[l].id]=0;
		cnt-=s[l].f;
		--l;
		while(!vis[s[r-1].id]&&cnt+s[r-1].f<=m) cnt+=s[r-1].f,vis[s[r-1].id]=1,--r; 
	}
	printf("%lld\n",ans);
	return 0;
}