#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N=100001;
ll m,n,a[N],b[N],s,c;
int main(){
	scanf("%lld %lld",&n,&m);
	for(ll i=1;i<=n;++i)scanf("%lld",&a[i]);
	for(ll i=1;i<=m;++i)scanf("%lld",&b[i]);
	sort(a+1,a+n+1);
	sort(b+1,b+m+1);
	for(ll i=1;i<=m;++i)
		if(a[c]==0)++c;
		else if(a[c]<b[i])++c,b[i]=0;
	if(c<=n)s=0;
	else for(int i=1;i<=m;++i)s+=b[i];
	printf("%d",s);
	return 0;
}