#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<ctime>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<stack>
using namespace std;
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn=1e5+10;
const int maxm=1e6+10;
const ll mod=1e9;
const ll base=1e8;
const ull base1=10007;
const ull base2=19260817;
const int maxxn=0x3f3f3f3f;
const int minxn=-0x3f3f3f3f;
const db inf=1e13;
const db eps=1e-9;
inline ll read(){
    ll x=0,w=1;char c=getchar();
    while(c<'0'||c>'9'){if(c=='-')w=-1;c=getchar();}
    while(c<='9'&&c>='0'){x=(x<<3)+(x<<1)+c-'0';c=getchar();}
    return x*w;
}
int n,m;
struct node{
    int id;
    int val,mx,mn;
}a[maxn];
bool cmp_val(node x,node y){
    return x.val<y.val;
}
bool cmp_mx(node x,node y){
    return x.mx<y.mx;
}
bool cmp_id(node x,node y){
    return x.id<y.id;
}
struct BinaryIndexTree{
    int num[maxn];
    BinaryIndexTree(){
        memset(num,-0x3f,sizeof(num));
    }
    inline int lowbit(int x){return x&-x;}
    inline void update(int x,int k){
        while(x<=n){
            num[x]=max(num[x],k);
            x+=lowbit(x);
        }
    }
    inline int query(int x){
        int res=-0x3f3f3f3f;
        while(x){
            res=max(res,num[x]);
            x-=lowbit(x);
        }
        return res;
    }
    inline void init(int x){
        while(x<=n){
            if(num[x]!=-0x3f3f3f3f) num[x]=-0x3f3f3f3f;
            else return;
            x+=lowbit(x);
        }
    }
}B;
int dp[maxn];
void cdq(int l,int r){
    #define mid ((l+r)>>1)
    if(l==r){
        dp[l]=max(dp[l],1);
        return;
    }
    cdq(l,mid);
    //printf("%d %d\n",l,r);
    sort(a+l,a+mid+1,cmp_mx);
    sort(a+mid+1,a+r+1,cmp_val);
    int i=l,j=mid+1;
    while(i<=mid&&j<=r){
        if(a[i].mx<=a[j].val){
            B.update(a[i].val,dp[a[i].id]);
            ++i;
        }
        else{
            dp[a[j].id]=max(dp[a[j].id],B.query(a[j].mn)+1);
            //printf("%d\n",dp[a[j].id]);
            ++j;
        }
    }
    while(j<=r){
        dp[a[j].id]=max(dp[a[j].id],B.query(a[j].mn)+1);
        //printf("%d\n",dp[a[j].id]);
        ++j;
    }
    while(i>=l){
        B.init(a[i].val);
        --i;
    }
    sort(a+l,a+r+1,cmp_id);
    cdq(mid+1,r);
    #undef mid
}
int ans;
int main(){
    n=read(),m=read();
    for(int i=1;i<=n;++i){
        a[i].id=i,a[i].val=a[i].mx=a[i].mn=read();
        dp[i]=-0x3f3f3f3f;
    }
    for(int i=1;i<=m;++i){
        int x=read(),k=read();
        a[x].mx=max(a[x].mx,k);
        a[x].mn=min(a[x].mn,k);
    }
    /*for(int i=1;i<=n;++i){
        printf("%d %d %d %d\n",i,a[i].val,a[i].mx,a[i].mn);
    }*/
    cdq(1,n);
    for(int i=1;i<=n;++i){
        //printf("%d\n",dp[i]);
        ans=max(ans,dp[i]);
    }
    printf("%d\n",ans);
    return 0;
}