#include<bits/stdc++.h> using namespace std; int m,n,a[1000086],b[1000086],s=0; int main() { cin>>m>>n; for(int i=1;i<=m;i++){ cin>>a[i]; } sort(a+1,a+m+1); for(int i=1;i<=n;i++){ cin>>b[i]; } sort(b+1,b+n+1); int l=1,r=n; for(int i=1;i<=n;i++){ if(b[i]==a[i]){ continue; }else if(b[i]<a[i]){ s+=a[i]-b[i]; }else if(b[i]>a[i]){ s+=b[i]-a[i]; } } cout<<s; return 0; }