#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn=100010;
int n,m,l,r,t,ans,maxx,p[maxn],a[maxn],b[maxn];
void Clear(int x){
	int i=t-1;
	while(i>=1){
		if(b[i]!=x)break;
		b[i]--,i--;
	}
	i=t+1;
	while(i<=maxx){
		if(b[i]!=x)break;
		b[i]--,i++;
	}
}
int main(){
	freopen("bg.in","r",stdin);
	freopen("bg.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)scanf("%d",&p[i]);
	sort(p+1,p+1+n);
	for(int i=1;i<=m;i++)scanf("%d%d",&l,&r),a[l]++,a[r+1]--,maxx=max(maxx,r);
	for(int i=1;i<=maxx+1;i++)b[i]=b[i-1]+a[i];
	for(int i=1;i<=m;i++){
		t=p[i];
		if(b[t])
			Clear(b[t]),ans++,b[t]--;
	}
	printf("%d\n",ans);
	return 0;
}