#include <bits/stdc++.h>
using namespace std;
#define needforspeed ios::sync_with_stdio(0);cin.tie(0);
#define int long long int
#define pb push_back
#define ins insert
#define endl '\n'
#define putr(x) cout<<x<<endl;return;
#define all(x) x.begin(),x.end()
#define _ << " " <<
const int mod = 1e9 +7,sze = 2e5 +23,inf = INT_MAX, L = 31;
int block;
int fener(pair<pair<int,int>,int> a, pair<pair<int,int>,int> b){
int x = a.first.first / block,y = b.first.first / block;
if(x!=y){
return a.first.first < b.first.first;
}
return a.first.second < b.first.second;
}
int tot =0;
int T[sze+23];
void upd(int node,int v){
node++;
while(node<=sze){
T[node]+=v;
node +=(node & -node);
}
}
int qry2(int node){
int sum=0;
node++;
while(node>0){
sum+=T[node];
node -= (node & -node);
}
return sum;
}
int qry(int node){
return qry2(sze) - qry2(node -1);
}
void ekle(int v){
tot+=v;
upd(v,1);
// cout<<"ekle: "<<v<<endl;
}
void sil(int v){
tot-=v;
upd(v,-1);
// cout<<"sil: "<<v<<endl;
}
void opt1z(){
int n,q;
cin>>n>>q;
block = ceil(sqrt(n));
vector<int> arr(n);
for(int i=0;i<n;i++){
cin>>arr[i];
}
vector<int> ans(q);
vector<pair<pair<int,int>,int>> qq;
for(int i=0;i<q;i++){
int l,r;
cin>>l>>r;l--;r--;
qq.pb({{l,r},i});
}
sort(all(qq),fener);
int cl = 0;
int cr = -1;
for(int i=0;i<q;i++){
int l=qq[i].first.first;
int r=qq[i].first.second;
int idx = qq[i].second;
while(cl>l){
cl--;
ekle(arr[cl]);
}
while(cr<r){
cr++;
ekle(arr[cr]);
}
while(cl<l){
sil(arr[cl]);
cl++;
}
while(cr>r){
sil(arr[cr]);
cr--;
}
int lx=1;
int rx = r-l+1;
int a=1;
while(lx<=rx){
int mid = (lx+rx)/2;
// cout<<mid<<endl;
if(qry(mid) >=mid){
a=mid;
lx = mid+1;
}
else{
rx = mid-1;
}
}
ans[idx]=a;
}
for(int i=0;i<q;i++) cout<<ans[i]<<endl;
}
signed main() {
needforspeed;
int tt = 1;
// cin>>tt;
while(tt--){
opt1z();
}
return 0;
}
