#include<bits/stdc++.h>

using namespace std;

#define re register int

const int N=100005;

struct node{

    int a,maxn,minn,bl;

}q[N];

bool comp0(node x,node y){return x.bl<y.bl;}

bool comp1(node x,node y){return x.maxn<y.maxn;}

bool comp2(node x,node y){return x.a<y.a;}

int n,m;

int tr[N],ans[N];

void add(int x,int v){

    for(re i=x;i<=n;i+=(i&(-i)))tr[i]=max(tr[i],v);

}

int query(int x){

    int ret=0;

    for(re i=x;i;i-=(i&(-i)))ret=max(ret,tr[i]);

    return ret;

}

void clear(int x){

    for(re i=x;i<=n;i+=(i&(-i))){

        if(tr[i]==0)break;

        tr[i]=0;

    }

}

void merge_sort(int l,int r){

    if(l>=r){

        ans[q[l].bl]=max(ans[q[l].bl],1);

        return ;

    }

    int mid=l+r>>1;

    merge_sort(l,mid);

    sort(q+l,q+mid+1,comp1);

    sort(q+mid+1,q+r+1,comp2);

    //cout<<l<<" "<<mid<<" "<<r<<" "<<q[l].a<<" "<<q[r].a<<endl;

    int i=l,j=mid+1;

    while(i<=mid&&j<=r){

        if(q[i].maxn<=q[j].a)add(q[i].a,ans[q[i].bl]),i++;

        else ans[q[j].bl]=max(ans[q[j].bl],query(q[j].minn)+1),j++;

    }

    while(i<=mid)add(q[i].a,ans[q[i].bl]),i++;

    while(j<=r)ans[q[j].bl]=max(ans[q[j].bl],query(q[j].minn)+1),j++;

    //cout<<query(q[j-1].minn)<<" "<<q[j-1].minn<<" "<<q[i-1].a<<" "<<ans[q[j-1].bl]<<endl;

    for(i=l;i<=mid;i++)clear(q[i].a);

    sort(q+l,q+r+1,comp0);

    merge_sort(mid+1,r);

}

signed main(){

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

    for(re i=1;i<=n;i++){

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

        q[i].a=x;q[i].maxn=x;q[i].minn=x;q[i].bl=i;

    }

    for(re i=1;i<=m;i++){

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

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

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

    }

    //for(re i=1;i<=n;i++)cout<<i<<" "<<q[i].a<<" "<<q[i].maxn<<" "<<q[i].minn<<endl;

    merge_sort(1,n);

    int sum=0;

    for(re i=1;i<=n;i++)sum=max(sum,ans[i]);

    printf("%d",sum);

}