#include<bits/stdc++.h>
using namespace std;
#define int long long
int n,m,a[100100],x,s;
signed main(){
cin>>n>>m;
for(int i=1;i<=n;i++) scanf("%lld",&a[i]);
sort(a+1,a+1+n);
int l,r,mid;
for(int i=1;i<=m;i++) {
scanf("%d",&x);
if(x<=a[1]) s=s+a[1]-x;
else if(x>=a[n]) s=s+x-a[n];
else{
l=1,r=n;
while(l<=r)
{
mid=r+l>>1;
if(x<=a[mid]) r=mid-1;
else l=mid+1;
}
s=s+min(a[l]-x,x-a[l-1]);
}
}
cout<<s;
return 0;
}