include<bits/stdc++.h>

using namespace std; struct youxi{

int t,money;

}a[505]; int k[505]; bool cmp(youxi x,youxi y){

return x.money>y.money;

} int main(){

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

}