#include <bits/stdc++.h>
 using namespace std;
 int minn=1000001;
int main()
{
    int s=0;
    int b[100001],a[100001],n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        cin>>b[i];
    for(int i=1;i<=m;i++)
    {
        cin>>a[i];
        for(int j=1;j<=n;j++)
          minn=min(abs(b[j]-a[i]),minn);
        s+=minn;    
        minn=1000001;
}
cout<<s;
return 0;
}