#include <bits/stdc++.h>
using namespace std;
int const N = 1e5 + 5;
unordered_map<int, int> cp;
int org[N];
int id = 0;
int qs[N], qe[N], qi[N], qa[N];
int n, m;
int arr[N];
int p1, p2;
int freq[N];
set<int> res;
void add(int x) {
  if (freq[x] == org[x]) {
    res.erase(x);
  }
  freq[x]++;
  if (freq[x] == org[x]) res.insert(x);
}
void del(int x) {
  if (freq[x] == org[x]) {
    res.erase(x);
  }
  freq[x]--;
  if (freq[x] == org[x]) res.insert(x);
}
void solve(int qn) {
  int a = qs[qn];
  int b = qe[qn];
  while (p2 <= b) {
    add(arr[p2++]);
  }
  while (p1 > a) {
    add(arr[--p1]);
  }
  while (p2 - 1 > b) {
    del(arr[--p2]);
  }
  while (p1 < a) {
    del(arr[p1++]);
  }
  qa[qn] = res.size();
}
void MO() {
  int sq = sqrt(n);
  sort(qi, qi + m, [sq](int a, int b) {
    return make_pair(qs[a] / sq, qe[a]) < make_pair(qs[b] / sq, qe[b]);
  });
  for (int i = 0; i < m; i++) {
    solve(qi[i]);
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> m;
  int x;
  for (int i = 0; i < n; i++) {
    cin >> x;
    if (cp.find(x) == cp.end()) {
      cp[x] = id;
      org[id++] = x;
    }
    arr[i] = cp[x];
  }
  for (int i = 0; i < m; i++) {
    qi[i] = i;
    cin >> qs[i] >> qe[i];
    qs[i]--;
    qe[i]--;
  }
  MO();
  for (int i = 0; i < m; i++) {
    cout << qa[i] << '\n';
  }
  return 0;
}
