#include <bits/stdc++.h>

    #define SQ 175

    const int MAXN = 3e4+10 ;

    using namespace std ;

    struct qry
    {
        int l , r , id ;
        bool operator < (qry other) const
        {
            if( l/SQ == other.l/SQ ) return r < other.r ;
            return l/SQ < other.l/SQ ;
        }
    } ;

    //MO algorithm
    int mainV[MAXN] , freq[MAXN]  , marcFreq[MAXN] ;

    void mo(int x, int val)
    {

        marcFreq[freq[x]] -- ;
        freq[x] += val ;
        marcFreq[ freq[x] ] ++ ;
    }

    int getAns()
    {
    	int tot = 0 ;
    	for(int i = MAXN ; i > 0 ; i-- )
    	{
    		tot += marcFreq[i] ;
    		if( tot >= i ) return i ;
    	}
    }


    int main()
    {
        int n , m ;
        qry q[MAXN] ;

        scanf("%d%d", &n, &m) ;
        for(int i = 1 ; i <= n ; i++ ) scanf("%d", &mainV[i] ) ;
        for(int i = 0 ; i < m; i++ )
            scanf("%d %d", &q[i].l, &q[i].r) , q[i].id = i ;

        //Coordinate compression
        map<int,int> myMap ;
        int key = 1 ;

        for(int i = 1 ; i <= n ; i++ )
            if(myMap.find(mainV[i]) == myMap.end() )
                myMap.insert( make_pair(mainV[i] , key++ ) ) ;

        //Main code
        sort(q,q+m) ;

        int l = 1 , r = 0 ;
        vector<int> myAns(MAXN) ;
        for(int i = 0 ; i < m ; i++ )
        {
            int newL = q[i].l , newR = q[i].r ;

            while( r < newR ) mo( myMap[ mainV[++r] ] , 1) ;
            while( l < newL ) mo( myMap[ mainV[l++] ] , -1) ;
            while( r > newR ) mo( myMap[ mainV[r--] ] , -1) ;
            while( l > newL ) mo( myMap[ mainV[--l] ] , 1) ;

            myAns[ q[i].id ] = getAns() ;

        }

        for(int i = 0 ; i < m ; i++) printf("%d\n" , myAns[i] ) ;

    }