#include<iostream>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<queue>
#include<vector>
#include<stack>
#include<cmath>
#include<algorithm>
#include<map>
#include<set>
#include<time.h>
using namespace std;
int N,M;
struct material
{
	int data,vis;
};
material mal[100000+10];
struct people
{
	int l,r,vis;
};
people pp[100000+10];
void read()
{
	cin>>N>>M;
	for(int i=1;i<=N;i++) 
	{
		mal[i].vis=1;
		cin>>mal[i].data;
	}
	for(int i=1;i<=M;i++)
	{
		pp[i].vis=1;
		 cin>>pp[i].l>>pp[i].r;
	}
}
int ans=0;
int judge()
{
	for(int i=1;i<=N;i++)
	{
		if(mal[i].vis)
		{
			for(int j=1;j<=M;j++)
			{
				if(mal[i].data<=pp[j].l&&mal[i].data>=pp[j].r)
				return 1;
			}
		}
	}
	return 0;
}
void sovle(int num)
{
	if(!judge()&&num>ans)
	{
		ans=num;
		return;
	}
	for(int i=1;i<=N;i++)
	{
		if(mal[i].vis)
		{
			for(int j=1;j<=M;j++)
			{
				if(pp[j].vis&&mal[i].data>=pp[j].l&&mal[i].data<=pp[j].r)
				{
					mal[i].vis=pp[j].vis=0;
					sovle(num+1);
					mal[i].vis=pp[j].vis=1;
				}
			}
		}
	}
}
int main()
{
	double start=clock(),end;
	freopen("bg.in","r",stdin);
	freopen("bg.out","w",stdout);
	read();
	sovle(0);
	cout<<ans<<endl;
	end=clock();
	//cout<<end-start<<endl;
	return 0;
}