#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int INF32 = INT_MAX;
const ll INF64 = ((ll)INF32 << 29ll);
void reflex() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr), cout.tie(nullptr);
}
const int N = 1e5 + 1e2;
struct Query {
  int l, r, id;
} q[N];
int n;
int f(int x) { return x / sqrt(n); }
bool cmp(Query x, Query y) {
  if (f(x.l) != f(y.l)) return f(x.l) < f(y.l);
  return x.r < y.r;
}
signed main() {
  reflex();
  int t;
  cin >> n >> t;
  vector<int> a(n);
  for (int& x : a) cin >> x;
  for (int i = 0, l, r; i < t; i++) {
    cin >> l >> r;
    l--, r--;
    q[i].l = l;
    q[i].r = r;
    q[i].id = i;
  }
  sort(q, q + t, cmp);
  unordered_map<int, int> cnt;
  int res = 0;
  auto add = [&](int x) {
    x = a[x];
    cnt[x]++;
    if (cnt[x] == x) res++;
    if (cnt[x] - 1 == x) res--;
  };
  auto del = [&](int x) {
    x = a[x];
    cnt[x]--;
    if (cnt[x] == x) res++;
    if (cnt[x] + 1 == x) res--;
  };
  int curl = q[0].l;
  int curr = curl;
  add(curl);
  vector<int> ans(t);
  for (int i = 0; i < t; i++) {
    int l = q[i].l;
    int r = q[i].r;
    int id = q[i].id;
    while (curl < l) del(curl++);
    while (curl > l) add(--curl);
    while (curr < r) add(++curr);
    while (curr > r) del(curr--);
    ans[id] = res;
  }
  for (int x : ans) cout << x << "\n";
  return false;
}
