#include <cstdlib>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <map>
#include <stack>
#include <vector>
#include <map>
#include <queue>
#include <ctime>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int uint;
const int inf=1061109567;
const int maxn=100010;
const int maxm=100010;
const int mod=998244353;
const double pi=3.14;

int a[maxn];
int pos[maxn];
int tmp[maxn];

int main()
{
    freopen("bg.in","r",stdin);
    freopen("bg.out","w",stdout);
    //clock_t st=clock();
    int n,m,l,r;scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
    sort(a+1,a+1+n);pos[0]=-inf;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&l,&r);
        pos[l]++;pos[r+1]--;
    }
    int t=0;
    for(int i=a[n];i>0;i--)
    {
        if(pos[i]<0) t=i;
        tmp[i]=t;
    }
    int sum=0,ans=0,cnt=1;
    for(int i=1;i<=a[n];i++)
    {
        sum+=pos[i];
        if(i==a[cnt])
        {
            if(sum>0)
            {
                sum--;
                ans++;
                t=tmp[i];
                while(pos[t]>=0) t=tmp[t+1];
                pos[t]++;
            }
            cnt++;
        }
    }
    printf("%d\n",ans);
    //clock_t ed=clock();
    //printf("\nTime used : %.5lf Ms\n",double(ed-st)/CLOCKS_PER_SEC);
    return 0;
}