#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb emplace_back
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<ii,ii> i4;
const int MOD=1000000007;
const int INF=1012345678;
const ll LLINF=1012345678012345678LL;
const double PI=3.1415926536;
const double EPS=1e-14;
int n,q;
int arr[200005];
struct node{
int s,e,m;
vector<int> v;
node *l,*r;
node(int S,int E){
s=S;e=E;m=(s+e)/2;
if(s==e){
v.pb(arr[s]);
}else{
l=new node(s,m);
r=new node(m+1,e);
int p1=0,p2=0;
for(int i=s;i<=e;i++){
if(p1==SZ(l->v)){
v.pb((r->v)[p2++]);
}else if(p2==SZ(r->v)){
v.pb((l->v)[p1++]);
}else{
if((l->v)[p1]<(r->v)[p2]){
v.pb((l->v)[p1++]);
}else{
v.pb((r->v)[p2++]);
}
}
}
}
}
int qry(int x,int y,int val){
if(s>=x&&e<=y){
int b=lower_bound(ALL(v),val)-v.begin();
return SZ(v)-b;
}
if(y<=m)return l->qry(x,y,val);
if(x>m)return r->qry(x,y,val);
return l->qry(x,m,val)+r->qry(m+1,y,val);
}
}*root;
int main(){
scanf("%d%d",&n,&q);
for(int i=0;i<n;i++)scanf("%d",&arr[i]);
root=new node(0,n-1);
int l,r;
while(q--){
scanf("%d%d",&l,&r);l--;r--;
int mini=0,maxi=r-l+1;
while(mini<maxi){
int mid=(mini+maxi+1)/2;
if(root->qry(l,r,mid)>=mid){ // number of papers from l to r with >=mid citations
mini=mid;
}else{
maxi=mid-1;
}
}
printf("%d\n",mini);
}
}
