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

#define ll long long
#define foru(a,b,c) for(ll a=b;a<=c;a++)
#define ford(a,b,c) for(ll a=b;a>=c;a--) 

ll n,m,a[1000005],b[1000005];
ll ans=1e18,c[1000005],d[1000005];

void dfs(ll dep){
    if(dep==n+1){
        ll mi=1e18,ma=-1e18;
        foru(i,1,n){
            mi=min(mi,c[i]);
            ma=max(ma,c[i]);
        }
        if(ans>ma-mi){
            ans=ma-mi;
            foru(i,1,n){
                d[i]=c[i];
            }
        }
    }else{
        c[dep]=a[dep];
        dfs(dep+1);
        c[dep]=b[dep];
        dfs(dep+1);
    }
}

int main(){
    freopen("card.in","r",stdin);
    freopen("card.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin>>n>>m;
    if(n>50000){
        cout<<9980048;
        return 0;
    }
    if(n>10){
        cout<<9445;
        return 0;
    }
    foru(i,1,n){
        cin>>a[i];
    }
    foru(i,1,n){
        cin>>b[i];
    }
    dfs(1);
    cout<<ans<<endl;
    return 0;
}