/*
Editor: Abdelrahman Hossam
Nickname: Blobo2_Blobo2
IOI next year isA :)
*/
/*#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.2,popcnt,abm,mmx,avx2,tune=native")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-funroll-all-loops,-fpeel-loops,-funswitch-loops")*/
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define all(v) v.begin(),v.end()
#define gen(arr,n,nxt) generate(arr,arr+n,nxt)
#define Blobo2_el_7akim_elly_3ayz_yro7_IOI_w_3ayz_yakol_jilaty ios_base::sync_with_stdio(false);cin.tie(0);
const int mo=1e9+7,INF=1e18;
int nxt(){int x;cin>>x;return x;}
signed main(){
Blobo2_el_7akim_elly_3ayz_yro7_IOI_w_3ayz_yakol_jilaty
int n=nxt(),m=nxt();
int left[max(n,m)],right[max(n,m)];
gen(left,n,nxt);
gen(right,m,nxt);
int szl=n,szr=m;
if(n>m){
int temp[n];
swap(szl,szr);
for(int i=0;i<n;i++)
temp[i]=left[i];
memset(left,0,sizeof left);
for(int i=0;i<m;i++)
left[i]=right[i];
memset(right,0,sizeof right);
for(int i=0;i<n;i++)
right[i]=temp[i];
}
sort(left,left+szl);
sort(right,right+szr);
int mx=0;
for(int i=0;i<szl;i++)
mx=max(mx,abs(left[i]-right[i]));
cout<<mx;
return 0;
}
