#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#define N 10005
#define int long long
#define ul unsigned long long
#define db double
#define b i&1
#define e i&1^1
#define fo(i,l,r) for(int i=l;i<=r;i++)
#define rf(i,r,l) for(int i=r;i>=l;i--)
using namespace std;
int n,m,f[2][N],x[N],y[N];
void swap(int &x,int &y){int t=x;x=y;y=t;}
int max(int x,int y){return x>y?x:y;}
int min(int x,int y){return x<y?x:y;}
bool cmp(int x,int y){return x>y;}
int read(){
	int sum=0;bool f=0;char c=getchar();
	for(;c<48||c>57;c=getchar())if(c==45)f=1;
	for(;c>=48&&c<=57;c=getchar())sum=sum*10+(c&15);
	return f?-sum:sum;
}
signed main(){
	freopen("chocolate.in","r",stdin);freopen("chocolate.out","w",stdout);
	n=read()-1;m=read()-1;
	fo(i,1,n)x[i]=read();
	fo(i,1,m)y[i]=read();
	sort(x+1,x+n+1,cmp);sort(y+1,y+m+1,cmp);
	fo(i,1,m)f[0][i]=f[0][i-1]+y[i];
	fo(i,1,n)
	{
		f[b][0]=f[e][0]+x[i];
		fo(j,1,m)
			f[b][j]=min(f[b][j-1]+y[j]*(i+1),f[e][j]+x[i]*(j+1));
	}
	printf("%lld",f[n&1][m]);
	return 0;
}