#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
using namespace std;
typedef pair <int, int> pii;
typedef long long ll;
const int NMAX = 1000001;
const int VMAX = 41;
const int INF = 1e9;
const int MOD = 1000000009;
const int BLOCK = 318;
const int base = 31;
const int nrbits = 21;
int a[NMAX], b[NMAX];
int n, m;
int f(int poz)
{
int maxim = 0;
for(int i = 1; i <= m; i++){
maxim = max(maxim, abs(a[i + poz - 1] - b[i]));
}
return maxim;
}
int ternary(int st, int dr){
if(st == dr - 1)
return min(f(st), f(dr));
int mid1 = st + (dr - st) / 3;
int mid2 = dr - (dr - st) / 3;
int f1 = f(mid1);
int f2 = f(mid2);
if(f1 < f2)
return ternary(st, f2 - 1);
return ternary(f1 + 1, dr);
}
int main() {
#ifdef HOME
ifstream cin(".in");
ofstream cout(".out");
#endif // HOME
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int i;
cin >> n >> m;
for(i = 1; i <= n; i++)
cin >> a[i];
for(i = 1; i <= m; i++)
cin >> b[i];
if(m > n){
for(i = 1; i <= m; i++){
swap(a[i], b[i]);
}
swap(n, m);
}
cout << ternary(1, n - m + 1);
return 0;
}
