#include <bits/stdc++.h>
#define ll long long
#define endl '\n'
using namespace std;
const int N = 200005;
int n,q,ar[N+3];
vector<int>seg[4*N+3];
void build(int i,int l,int r){
if(l==r){
seg[i].emplace_back(ar[l]);
return;
}
int mid=l+(r-l)/2;
build(i*2,l,mid); build(i*2+1,mid+1,r);
seg[i].reserve(seg[i*2].size()+seg[i*2+1].size());
merge(seg[i*2].begin(),seg[i*2].end(),seg[i*2+1].begin(),seg[i*2+1].end(),back_inserter(seg[i]));
}
int que(int i,int l,int r,int ql,int qr,int x){
if(r<ql||l>qr)return 0;
else if(l>=ql&&r<=qr){
int it=lower_bound(seg[i].begin(),seg[i].end(),x)-seg[i].begin();
return seg[i].size()-it;
}
int mid=l+(r-l)/2;
return que(i*2,l,mid,ql,qr,x)+que(i*2+1,mid+1,r,ql,qr,x);
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cin>>n>>q;
for(int i=1;i<=n;i++){
cin>>ar[i];
}
build(1,1,n);
while(q--){
int L,R;cin>>L>>R;
int l=1,r=R-L+1,ans=0;
while(l<=r){
int mid=l+(r-l)/2;
if(que(1,1,n,L,R,mid)>=mid){
ans=mid;
l=mid+1;
}
else r=mid-1;
}
cout<<ans<<endl;
}
}
/*
*/
