#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n, m;
  scanf("%d %d\n", &n, &m);
  vector<int> v(n);
  vector<pair<int, pair<int, int>>> q(m);
  for (int i = 0; i < n; i++) {
    scanf("%d ", &v[i]);
  }
  for (int i = 0; i < m; i++) {
    int l, r;
    scanf("%d %d", &l, &r);
    q[i] = {i, {l - 1, r - 1}};
  }
  sort(q.begin(), q.end(),
       [](pair<int, pair<int, int>> a, pair<int, pair<int, int>> b) {
         return a.second.second < b.second.second;
       });
  vector<int> res(q.size());
  for (int a = 0, b = 300; a < v.size(); a += 300, b += 300) {
    unordered_map<int, int> map;
    int l = a, r = a - 1;
    int cnt = 0;
    for (auto pp : q) {
      if (pp.second.first < a || pp.second.first >= b) continue;
      while (r < pp.second.second) {
        map[v[++r]]++;
        if (v[r] == map[v[r]]) cnt++;
        if (map[v[r]] - v[r] == 1) cnt--;
      }
      while (l > pp.second.first) {
        map[v[--l]]++;
        if (v[l] == map[v[l]]) cnt++;
        if (map[v[l]] - v[l] == 1) cnt--;
      }
      while (l < pp.second.first) {
        if (v[l] == map[v[l]]) cnt--;
        map[v[l]]--;
        if (v[l] == map[v[l]]) cnt++;
        l++;
      }
      res[pp.first] = cnt;
    }
  }
  for (int e : res) printf("%d\n", e);
}
