#include<cstdio>

 #include<cstring>

 #include<algorithm>

 #define LL long long

 #define rg register

 #define N 100010

 #define ls (u<<1)

 #define rs (u<<1|1)

 using namespace std;

 int n,m,ans,mn[N<<],del[N<<];

 struct seg{

     int l,r;

 }a[N];

 inline int read(){

     int k=,f=; char c=getchar();

     while(c<''||c>'')c=='-'&&(f=-),c=getchar();

     while(''<=c&&c<='')k=k*+c-'',c=getchar();

     return k*f;

 }

 void build(int u,int l,int r){

     if(l<r){

         int mid=(l+r)>>;

         build(ls,l,mid),build(rs,mid+,r),mn[u]=min(mn[ls],mn[rs]);

     }

     else mn[u]=read();

 }

 inline void pushdown(int u){

     mn[ls]+=del[u]; del[ls]+=del[u];

     mn[rs]+=del[u]; del[rs]+=del[u];

     del[u]=;

 }

 void update(int u,int l,int r,int ul,int ur){

     if(ul<=l&&r<=ur){

         mn[u]--; del[u]-=;

         return;

     }

     int mid=(l+r)>>; pushdown(u);

     if(ul<=mid) update(ls,l,mid,ul,ur);

     if(ur>mid) update(rs,mid+,r,ul,ur);

     mn[u]=min(mn[ls],mn[rs]);

 }

 int query(int u,int l,int r,int ul,int ur){

     if(ul<=l&&r<=ur) return mn[u];

     int mid=(l+r)>>,ret=2e9; pushdown(u);

     if(ul<=mid) ret=min(ret,query(ls,l,mid,ul,ur));

     if(ur>mid) ret=min(ret,query(rs,mid+,r,ul,ur));

     return ret;

 }

 inline bool cmp(seg a,seg b){

     if(a.r==b.r) return a.l>b.l;

     return a.r<b.r;

 }

 int main(){

     n=read(); m=read(); build(,,n);

     for(rg int i=;i<=m;i++) a[i].l=read(),a[i].r=read();

     sort(a+,a++m,cmp);

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

         int tmp=query(,,n,a[i].l,a[i].r);

         if(tmp>){

             ans++;

             update(,,n,a[i].l,a[i].r);

         }

     }

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

     return ;

 }