#include <bits/stdc++.h>
using namespace std;
long long school,student,k,cnt,ans,a[1000010],b[1000010];

int main()
{
	cin>>school>>student;
	for(int i = 0 ; i < school ; i ++)
	{
		cin>>a[i];//学校 
	}
	for(int i = 0 ; i < student ; i ++)
	{
		cin>>b[i];//学生 
	}
	for(int i = 0 ; i < student ; i++)
	{
		cnt = INT_MAX;
		for(int j = 0 ; j < school ; j++)
		{
			if(abs(b[i] - a[j]) < cnt)
			{
				cnt = abs(b[i] - a[j]);
			}
		}
		ans += cnt;
	}
	cout<<ans;
	return 0;
}

懵了，五个TLE