#include <bits/stdc++.h>
using namespace std;
struct data {
  int l, r, id;
};
int n, m, S, ans;
vector<data> query;
int ans_query[1000000], a[1000000], cnt[1000000];
bool operator<(data x, data y) {
  if (x.r / S != y.r / S) return (x.r / S) < (y.r / S);
  return x.l < y.l;
}
void add(int x) {
  if (x > n || x == 0) return;
  if (cnt[x] == x) ans--;
  cnt[x]++;
  if (cnt[x] == x) ans++;
}
void sub(int x) {
  if (x > n || x == 0) return;
  if (cnt[x] == x) ans--;
  cnt[x]--;
  if (cnt[x] == x) ans++;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  S = sqrt(n);
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i <= m; i++) {
    int l, r;
    cin >> l >> r;
    query.push_back({l, r, i});
  }
  sort(query.begin(), query.end());
  int L = 0, R = 0;
  for (int i = 0; i < query.size(); i++) {
    int l = query[i].l, r = query[i].r, pos = query[i].id;
    while (R < r) add(a[++R]);
    while (L < l) sub(a[L++]);
    while (R > r) sub(a[R--]);
    while (L > l) add(a[--L]);
    ans_query[pos] = ans;
  }
  for (int i = 1; i <= m; i++) cout << ans_query[i] << "\n";
  return 0;
}
