#include<bits/stdc++.h>
#define re register
#define debug(...) fprintf(stderr,__VA_ARGS__);
using namespace std;
typedef long long ll;
typedef double db;
inline ll win(){
	ll x=0;bool w=0;char c=getchar();
	while(c<'0'||c>'9') w|=c=='-',c=getchar();
	while(c<='9'&&c>='0') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return w?-x:x;
}

const int N=202020;
const int inf=0x3f3f3f3f;
int st[21][N],ps[N],vl[N];

inline int bnd(int i,int lm){
	for(re int k=20;k>=0;--k)
		if(st[k][i]>=lm) i+=(1<<k);
	return i;
}

inline void sol(int n,int m,int *a,int *b,bool *t){
	int l=0;
	for(re int i=1,mx=-inf;i<=n;++i) if(mx<a[i]) mx=a[i],ps[++l]=i,vl[l]=a[i];
	memset(st,0xbf,sizeof st);
	for(re int i=1;i<=m;++i) st[0][i]=b[i];
	for(re int k=0;k<20;++k)
		for(re int i=1,j=(1<<k)+1,lj=m-(1<<k)+1;j<=lj;++i,++j)
			st[k+1][i]=min(st[k][i],st[k][j]);
	for(re int i=m,la=m+1,j,k;i>=1;--i){
		//first >b[i]
		if(b[i]>=vl[l]) t[i]=1,la=i;
		else{
			j=ps[upper_bound(vl+1,vl+l+1,b[i])-vl]-1;
//			debug("%d:%d\n",i,j);
			if(j){
				k=bnd(i,a[j])-1;//first <a[j]
				if(la<=k) t[i]=1,la=i;
			}
		}
	}
}

int a[N],b[N];bool tx[N],ty[N];
inline void rmain(){
	int m=win(),n=win(),mna=inf,mxa=-inf;ll ans=0;
	for(re int i=1;i<=m;++i) b[i]=win();
	for(re int i=1;i<=n;++i) a[i]=-win(),mna=min(mna,a[i]),mxa=max(mxa,a[i]);
	sol(n,m,a,b,tx);
	reverse(a+1,a+n+1),reverse(b+1,b+m+1);
	sol(n,m,a,b,ty);
	reverse(a+1,a+n+1),reverse(b+1,b+m+1);
	reverse(ty+1,ty+m+1);
//	for(re int i=1;i<=m;++i) debug("%d:%d %d\n",i,tx[i],ty[i]);
	for(re int i=m,yn=0,yc=0;i>=1;--i){
		if(b[i]<mna) yn=yc=0;
		if(ty[i]) ++yn;
		if(b[i]>=mxa) yc+=yn,yn=0;
		if(tx[i]) ans+=yc;
	}
	printf("%lld\n",ans);
}

signed main(){
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
//	int T=win();while(T--)
	rmain();
	return 0;
}