#include <algorithm>

 #include <iostream>

 #include <cstdlib>

 #include <cstring>

 #include <cstdio>

 #include <cmath>

 using namespace std;

 const int N=,INF=2e8;

 int gi(){

     int str=;char ch=getchar();

     while(ch>'' || ch<'')ch=getchar();

     while(ch>='' && ch<='')str=(str<<)+(str<<)+ch-,ch=getchar();

     return str;

 }

 int n,m,f[N];

 struct node{

     int x,L,R,id;

 }a[N];

 bool compid(const node &px,const node &qx){

     return px.id<qx.id;

 }

 bool compL(const node &px,const node &qx){

     return px.L<qx.L;

 }

 bool compx(const node &px,const node &qx){

     return px.x<qx.x;

 }

 int Tree[N<<],st[N<<],top=;

 void add(int sta,int x){

     for(int i=sta;i<=n;i+=(i&(-i))){if(x>Tree[i])Tree[i]=x;}

 }

 int query(int sta){

     int ret=;

     for(int i=sta;i>=;i-=(i&(-i)))if(Tree[i]>ret)ret=Tree[i];

     return ret;

 }

 void Clear(int sta){

     for(int i=sta;i<=n;i+=(i&(-i)))Tree[i]=;

 }

 int ans=;

 void cdq(int l,int r){

     if(l==r)return ;

     int mid=(l+r)>>;

     cdq(l,mid);

     sort(a+l,a+mid+,compx);sort(a+mid+,a+r+,compL);

     int t1=l,t2=mid+;

     while(t1<=mid && t2<=r){

         if(a[t1].x<=a[t2].L)st[++top]=a[t1].R,add(a[t1].R,f[a[t1].id]),t1++;

         else f[a[t2].id]=max(f[a[t2].id],query(a[t2].x)+),t2++;

     }

     while(t2<=r){

         f[a[t2].id]=max(f[a[t2].id],query(a[t2].x)+);t2++;

     }

     while(top)Clear(st[top--]);

     sort(a+mid+,a+r+,compid);

     cdq(mid+,r);

 }

 void work(){

     int x,y;

     n=gi();m=gi();

     for(int i=;i<=n;i++)a[i].x=gi(),a[i].L=a[i].R=a[i].x,a[i].id=i,f[i]=;

     for(int i=;i<=m;i++){

         x=gi();y=gi();

         if(y>a[x].R)a[x].R=y;

         if(y<a[x].L)a[x].L=y;

     }

     cdq(,n);

     for(int i=;i<=n;i++)if(f[i]>ans)ans=f[i];

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

 }

 int main()

 {

     freopen("heoi2016_seq.in","r",stdin);

     freopen("heoi2016_seq.out","w",stdout);

     work();

     return ;

 }