include<bits/stdc++.h>

using namespace std; int m,n,b[505],k,ans; struct xm{

int shi,jin;

}a[505]; bool cmp(xm a,xm b){

return a.jin>b.jin;

} int main(){ // freopen("name.in","r",stdin); // freopen("name.out","w",stdout);

cin>>m>>n;
for(int i=1;i<=n;i++) cin>>a[i].shi;
for(int i=1;i<=n;i++) cin>>a[i].jin;
sort(a+1,a+n+1,cmp);
for(int i=1;i<=n;i++){
	for(int j=a[i].shi;j>=1;j--)
		if(b[j]==0){
			k=1;
			b[j]=1;
			break;
		}
	if(k==0)
		ans+=a[i].jin;
	k=0;
}
cout<<m-ans;
return 0;

}