#include <map>

#include <cmath>

#include <queue>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

#define F(i,j,k) for (int i=j;i<=k;++i)

#define D(i,j,k) for (int i=j;i>=k;--i)

#define ll long long

#define mp make_pair

#define maxn 200005

struct node{

    int a,b,c,id,ans;

    void print()

    {printf("ID is %d Upper %d Middle %d Lower %d\n",c,b,a);}

}q[maxn];

int n,m;

bool cmp1(node x,node y){return x.b<y.b;}

bool cmp2(node x,node y){return x.a<y.a;}

bool cmp3(node x,node y){return x.id<y.id;}

int bit[maxn];

void add(int x,int f)

{

    for (;x<maxn;x+=x&(-x)) bit[x]=max(bit[x],f);

}

void del(int x)

{

    for (;x<maxn;x+=x&(-x)) bit[x]=0;

}

int query(int x)

{

    int ret=0;

    for (;x;x-=x&(-x)) ret=max(ret,bit[x]);

    return ret;

}

void CDQ(int l,int r)

{

    if (l==r) return;

    int mid=l+r>>1;

    sort(q+l,q+r+1,cmp3);

    CDQ(l,mid);

    sort(q+l,q+mid+1,cmp1);

    sort(q+mid+1,q+r+1,cmp2);

    int now=l;

    F(i,mid+1,r)

    {

        while (now<=mid&&q[now].b<=q[i].a) add(q[now].c,q[now].ans),now++;

        q[i].ans=max(q[i].ans,query(q[i].b)+1);

    }

    F(i,l,now-1) del(q[i].c);

    CDQ(mid+1,r);

}

int main()

{

    scanf("%d%d",&n,&m);

    F(i,1,n)

    {

        scanf("%d",&q[i].b);

        q[i].a=q[i].c=q[i].b;

        q[i].id=i; q[i].ans=1;

    }

    F(i,1,m)

    {

        int x,y;

        scanf("%d%d",&x,&y);

        q[x].a=min(q[x].a,y);

        q[x].c=max(q[x].c,y);

    }

    CDQ(1,n);

    int ans=0;

    F(i,1,n) ans=max(ans,q[i].ans);

    printf("%d\n",ans);

}