#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdio>
using namespace std;

const int N = 100005, Nr = 450, inf = 0x3f3f3f3f;
int val[N], a[N], n, nrP, nrQ;
vector<int> app[N];

struct Query{
    int nrAp[Nr], x, y;

    Query(){
        x = y = 0;
    }

    Query(int _x, int _y){
        x = _x;
        y = _y;
    }

    void upt(int poz, int val){
        nrAp[poz] += val;
    }

    int ans(){
        int rez = 0;

        for (int i = 1 ; i <= nrP ; i++)
            if (nrAp[i] == val[i])
                ++rez;

        return rez;
    }
} query[N];

struct Per{
    int Q, x, y;

    void operator=(const Query& X){
        Q = (&X) - query;
        x = X.x;
        y = X.y;
    }
} ord[N];

inline bool dupaX(const Per& X, const Per& Y){
    return X.x < Y.x;
}

inline bool dupaY(const Per& X, const Per& Y){
    return X.y > Y.y;
}

void get_data(){
    int x;

    cin >> n >> nrQ;

    for (int i = 1 ; i <= n ; i++)
        app[i].push_back(-inf);

    for (int i = 1 ; i <= n ; i++){
        cin >> x;

        if (x && x <= n)
            app[x].push_back(i);
    }

    for (int i = 1 ; i <= n ; i++)
        app[i].push_back(inf);

    for (int i = 1 ; i <= nrQ ; i++){
        cin >> query[i].x >> query[i].y;
        ord[i] = query[i];
    }
}

void normalise(){
    for (int i = 1 ; i <= n ; i++)
        if (i + 2 <= app[i].size()){
            val[++nrP] = i;

            if (nrP != i)
                app[nrP].swap(app[i]);
        }

}

void compute(){
    normalise();

    sort(ord + 1, ord + nrQ + 1, dupaX);

    for (int x = 1 ; x <= nrP ; x++)
        for (int i = 0 , j = 1 ; i < app[x].size() ; i++)
            for ( ; j <= nrQ && ord[j].x <= app[x][i] ; j++)
                query[ ord[j].Q ].upt(x, -i + 1);

    sort(ord + 1, ord + nrQ + 1, dupaY);

    for (int x = 1 ; x <= nrP ; x++)
        for (int i = app[x].size() - 1 , j = 1 ; i >= 0 ; i--)
            for ( ; j <= nrQ && ord[j].y >= app[x][i] ; j++)
                query[ ord[j].Q ].upt(x, i);
}

void print(){
    for (int i = 1 ; i <= nrQ ; i++)
        cout << query[i].ans() << "\n";
}

int main(){
    #ifndef ONLINE_JUDGE
        freopen("cf.in", "r", stdin);
        freopen("cf.out", "w", stdout);
    #endif

    get_data();

    compute();

    print();

    return 0;
}