/*
Author: Teoman Ata Korkmaz
*/
#pragma GCC optimize("O3,fast-math,unroll-loops")
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define ff first
#define ss second
#define endl '\n'
#define spc ' '
#define pb push_back
#define e2(x) (1LL<<(x))
#define lg(x) (__lg(x))
#define gcd(x,y) __gcd(x,y)
#define lcm(x,y) ((x/gcd(x,y))*y)
#define smrt(i) (double(sqrt(8*(i)+1)-1)/2)
#define ssum(x) ((x)*((x)+1)/2)
#define isint(x) (ceil((x))==floor((x)))
#define no cout<<"NO"<<endl
#define yes cout<<"YES"<<endl
#define cendl cout<<endl
#define mset(x,y) memset(x,y,sizeof(x))
#define popcnt(x) __builtin_popcountll(x)
#define clz(x) __builtin_clz(x)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define clock() (chrono::high_resolution_clock::now().time_since_epoch().count())
#define compress(x) sort(all(x));x.resize(unique(all(x))-x.begin())
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);cerr.tie(NULL);cout<<fixed<<setprecision(0);cerr<<fixed<<setprecision(0)
#define fileio freopen("out.txt","w",stdout);freopen("in.txt","r",stdin)
#define usacoio(s) freopen((s + str(".in")).c_str(), "r", stdin);freopen((s + str(".out")).c_str(), "w", stdout)
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
using namespace std;
//using namespace __gnu_pbds;
typedef int_fast32_t i32;
typedef int_fast64_t ll;
typedef long double ldouble;
typedef string str;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef pair<ii,ii> iiii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pair<char,int>> vci;
typedef vector<str> vstr;
typedef map<int,int> mii;
typedef map<char,int> mci;
typedef map<str,int> msi;
typedef map<int,vi> miv;
typedef unordered_map<int,int> umii;
typedef unordered_map<char,int> umci;
typedef unordered_map<str,int> umsi;
typedef unordered_map<int,vi> umiv;
typedef set<int> sti;
typedef set<char> stc;
typedef set<str> sts;
typedef multiset<int> msti;
typedef multiset<char> mstc;
typedef multiset<str> msts;
inline int segsum(int start,int end,int step){
if(end<start)return 0;
return (((end-start)/step+1)*(start+end))>>1;
}
inline int fp(int b,int p,int mod=1e9+7){
int ans=1;
while(p){
if(p&1)ans=(ans*b)%mod;
p>>=1;
b=(b*b)%mod;
}
return ans;
}
template<typename InputIterator,typename T = int>
T accumulate(InputIterator first,InputIterator last,T init = T{}) {
for (; first != last; ++first) {
init += *first;
}
return init;
}
template<typename T,typename T2>inline pair<T,T2> operator+(const pair<T,T2>&a,const pair<T,T2>& b){return {a.ff+b.ff,a.ss+b.ss};}
template<typename T,typename T2>inline pair<T,T2> operator-(const pair<T,T2>&a,const pair<T,T2>& b){return {a.ff-b.ff,a.ss-b.ss};}
template<typename T,typename T2>inline pair<T,T2> operator*(const pair<T,T2>&a,const pair<T,T2>& b){return {a.ff*b.ff,a.ss*b.ss};}
template<typename T,typename T2>inline pair<T,T2> operator/(const pair<T,T2>&a,const pair<T,T2>& b){return {a.ff/b.ff,a.ss/b.ss};}
template<typename T> inline void maxs(T& x,const T& y){return void(x=max(x,y));}
template<typename T> inline void mins(T& x,const T& y){return void(x=min(x,y));}
template<typename T> inline void gcds(T& x,const T& y){return void(x=gcd(x,y));}
template<typename T> inline void lcms(T& x,const T& y){return void(x=lcm(x,y));}
template<typename T,typename T2>inline ostream& operator<<(ostream& os, const pair<T,T2>& p){
os<<"["<<p.ff<<","<<p.ss<<"]";
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const vector<T>& a) {
for(const T& _:a)os<<_<<' ';
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const vector<vector<T>>& a) {
for(const vector<T>& _:a)os<<_<<endl;
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const set<T>& a) {
for(const T& _:a)os<<_<<' ';
return os;
}
template<typename T,typename T2>inline ostream& operator<<(ostream& os,const map<T,T2>& a) {
for(const auto& _:a)os<<_<<' ';
return os;
}
template<typename T,typename T2>inline ostream& operator<<(ostream& os,const unordered_map<T,T2>& a) {
for(const auto& _:a)os<<_<<' ';
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const queue<T>& b) {
queue<T> a=b;
while(a.size()){
os<<a.front()<<" ";
a.pop();
}
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const stack<T>& b) {
stack<T> a=b;
while(a.size()){
os<<a.top()<<" ";
a.pop();
}
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const priority_queue<T>& b) {
priority_queue<T> a=b;
while(a.size()){
os<<a.top()<<" ";
a.pop();
}
return os;
}
template<typename T>inline ostream& operator<<(ostream& os,const priority_queue<T,vector<T>,greater<T>>& b) {
priority_queue<T,vector<T>,greater<T>> a=b;
while(a.size()){
os<<a.top()<<" ";
a.pop();
}
return os;
}
template<typename T,typename T2>inline istream& operator>>(istream& is,pair<T,T2>& p){
is>>(p.ff)>>(p.ss);
return is;
}
template<typename T>inline istream& operator>>(istream& is,vector<T>& a) {
for(T& _:a)is>>_;
return is;
}
inline void print(){cout<<endl;}
template<typename... Args>
inline void print(const Args&... args){
((cout<<args<<' '),...)<<endl;
}
inline void input(){}
template<typename... Args>
inline void input(Args&... args){
(cin>>...>>args);
}
#ifdef ONLINE_JUDGE
template<typename... Args>
inline void debug(const Args&... args){
return void("59");
}
#else
inline void debug(){cerr<<endl;}
template<typename... Args>
inline void debug(const Args&... args){
((cerr<<args<<' '),...)<<endl;
}
#endif
inline void yn(bool b){
if(b)yes;
else no;
}
#define ASSERT(condition, message)\
if(condition){\
cerr<<"Assertion failed: "<<message<<" at "<<__FILE__<<":"<<to_string(__LINE__)<<endl;\
abort();\
}
///////////////////////////////////////////////////////////////////
const int N=2e5+5;
const int A=1e9+5;
const int MOD=1e9+7;
const i32 INF=INT32_MAX;
const ll INFL=INT64_MAX;
const int BLOCK=448;
const ldouble EPS=1e-9;
const int MAXQUERY=100;
const double PI=4*atan(1);
const int dx[4]={-1,0,1,0};
const int dy[4]={0,1,0,-1};
mt19937 mt(clock());
///////////////////////////////////////////////////////////////////
int n,m,k,t,q,a,b,x,y,w;
vi v;
struct Node{
int val;
Node* left;
Node* right;
Node(int x=0):val(x),left(NULL),right(NULL){}
Node(Node* x):val(x->val),left(x->left),right(x->right){}
Node(Node* l,Node* r){
left=l,right=r,val=0;
if(l)val+=l->val;
if(r)val+=r->val;
}
};
#define mid ((l+r)>>1)
inline Node* build(int l=1,int r=n){
if(l==r)return new Node(1);
else return new Node(build(l,mid),build(mid+1,r));
}
inline Node* update(Node* node,int l=1,int r=n){
//debug("u! l,r,x:",l,r,x);
if(l==r) return new Node(int(0));
if(x<=mid)return new Node(update(node->left,l,mid),node->right);
else return new Node(node->left,update(node->right,mid+1,r));
}
inline int query(Node* node,int l=1,int r=n){
if(x<=l && r<=y)return node->val;
if(r<x || y<l)return 0;
return query(node->left,l,mid)+query(node->right,mid+1,r);
}
inline void _debug(Node* root){
queue<Node*> q;
q.push(root);
while(q.size()){
Node* node=q.front();q.pop();
if(node==NULL)continue;
cerr<<(node->val)<<" ";
q.push(node->left);
q.push(node->right);
}
debug();
}
#undef mid
inline void solve(void){
Node* root[N];
input(n,q);
v.resize(n);
input(v);
vvi arr(*max_element(all(v))+2);
for(int i=0;i<n;i++)arr[v[i]].pb(i+1);
root[1]=build();
//_debug(root[1]);
//debug("build ok");
for(int i=2;i<arr.size();i++){
root[i]=new Node(root[i-1]);
for(auto j:arr[i-1]){
x=j;
root[i]=update(root[i]);
}
//debug("update",i,"ok");,
//_debug(root[i]);
}
//debug("updates ok");
while(q--){
input(x,y);
int l=1,r=y-x+2;
while(l<r){
int m=(l+r)>>1;
if(query(root[m])>=m)l=m+1;
else r=m;
}
print(l-1);
}
}
signed main(void){
int start=clock();
fastio;
//usacoio("59");
int t=1;
//cin>>t;
while(t--)solve();
debug("Time elapsed:",(clock()-start)/(1e6),"ms");
}
