#include <bits/stdc++.h>
using namespace std;
int sc1() {
  int x;
  scanf("%d", &x);
  return x;
}
long long sc2() {
  long long x;
  scanf("%lld", &x);
  return x;
}
int bs;
int n, q;
int arr[100007];
int cnt[100007];
int ans = 0;
int answer[100007];
struct A {
  int l, r, id;
} node[100007];
bool cmp(A a, A b) {
  int x = a.l / bs;
  int y = b.l / bs;
  if (x != y) return x < y;
  return a.r < b.r;
}
void add(int x) {
  if (x <= n) {
    if (cnt[x] == x) ans--;
    cnt[x]++;
    if (cnt[x] == x) ans++;
  }
}
void rmv(int x) {
  if (x <= n) {
    if (cnt[x] == x) ans--;
    cnt[x]--;
    if (cnt[x] == x) ans++;
  }
}
int main() {
  n = sc1(), q = sc1();
  bs = sqrt(n);
  for (int i = 0; i < n; i++) arr[i] = sc1();
  for (int i = 0; i < q; i++) {
    int a = sc1(), b = sc1();
    node[i].l = --a;
    node[i].r = --b;
    node[i].id = i;
  }
  sort(node, node + q, cmp);
  int mo_left = 0, mo_right = -1;
  for (int i = 0; i < q; i++) {
    int left = node[i].l;
    int right = node[i].r;
    while (mo_right < right) {
      mo_right++;
      add(arr[mo_right]);
    }
    while (mo_right > right) {
      rmv(arr[mo_right]);
      mo_right--;
    }
    while (mo_left < left) {
      rmv(arr[mo_left]);
      mo_left++;
    }
    while (mo_left > left) {
      mo_left--;
      add(arr[mo_left]);
    }
    answer[node[i].id] = ans;
  }
  for (int i = 0; i < q; i++) {
    cout << answer[i] << endl;
  }
  return 0;
}
