？Subtask #1？

#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
int mian;
int n,a[114514]={0},b[114514]={0},l,r;
ll ans=0;
int er(int k){
    l=1;
    r=mian;
    while(l<r){
        int m=(l+r+1)/2;
        if(a[m]<k) l=m;
        else r=m-1;
    }
    return l;
}
const int maxx=0x3f3f3f,minn=-0x3f3f3f;
int main(){
//  freopen("doc.in","r",stdin);
//  freopen("doc.out","w",stdout);
    cin>>mian>>n;
    for(int i=1;i<=mian;i++){
        cin>>a[i];
    }
    for(int i=1;i<=n;i++){
        cin>>b[i];
    }
    sort(a+1,a+mian+1);
    for(int i=1;i<=n;i++){
        int t=er(b[i]);
            ans+=min(abs(a[t]-b[i]),abs(a[t+1]-b[i]));
    }
    printf("%lld",ans);
    return 0;
}