#include <iostream>
#include <cstdio>
using namespace std;
int n,m;
struct QwQ{
	int n,val[200005];
	int log_2[200005],mn[20][200005],mx[20][200005];
	void init(int _n){
		n=_n;
		for (int i=1;i<=n;i++)scanf("%d",&val[i]);
		for (int i=2;i<=n;i++)log_2[i]=log_2[i/2]+1;
		for (int i=1;i<=n;i++){
			mn[0][i]=val[i];
			mx[0][i]=val[i];
		}
		for (int w=1;w<20;w++)
			for (int i=1;i+(1<<w)-1<=n;i++){
				mn[w][i]=min(mn[w-1][i],mn[w-1][i+(1<<(w-1))]);
				mx[w][i]=max(mx[w-1][i],mx[w-1][i+(1<<(w-1))]);
			}
		return;
	}
	int askmn(int l,int r){
		int w=log_2[r-l+1];
		return min(mn[w][l],mn[w][r-(1<<w)+1]);
	}
	int askmx(int l,int r){
		int w=log_2[r-l+1];
		return max(mx[w][l],mx[w][r-(1<<w)+1]);
	}
}a,b;
int f[200005],t[200005],g[200005];
int sum[200005];
int ans;
int main(){
	cin>>m>>n;
	b.init(m);
	a.init(n);
	int last=-1;
	for (int i=m;i>=1;i--){
		int l=1,r=n,p=0;
		while(l<=r){
			int mid=(l+r)/2;
			if (a.askmn(1,mid)+b.val[i]>=0)p=mid,l=mid+1;
			else r=mid-1;
		}
		if (p==0)continue;
		int val_a=a.askmx(1,p);
		l=i,r=m;
		while(l<=r){
			int mid=(l+r)/2;
			if (val_a+b.askmn(i,mid)>=0)t[i]=mid,l=mid+1;
			else r=mid-1;
		}
		if (p==n||(last!=-1&&t[i]>=last)){
			f[i]=1;
			last=i;
		}
	}
	last=-1;
	for (int i=1;i<=m;i++){
		int l=1,r=n,p=n+1;
		while(l<=r){
			int mid=(l+r)/2;
			if (a.askmn(mid,n)+b.val[i]>=0)p=mid,r=mid-1;
			else l=mid+1;
		}
		if (p==n+1)continue;
		if (p==1||(last!=-1&&a.askmx(p,n)+b.askmn(last,i))>=0){
			g[i]=1;
			last=i;
		}
	}
	for (int i=m;i>=1;i--)sum[i]=sum[i+1]+g[i];
	last=-1;
	for (int i=m;i>=1;i--){
		if (a.askmn(1,n)+b.val[i]>=0)last=i;
		if (f[i]==1&&last!=-1)ans+=sum[last];
	}
	cout<<ans<<endl;
	return 0;
}