#include <bits/stdc++.h>
using namespace std;
int main(void) {
  long n, m, l, r;
  vector<long> a(100005);
  map<long, vector<long> >::iterator mi;
  vector<long>::iterator vi1, vi2;
  map<long, vector<long> > hash;
  scanf("%ld %ld", &n, &m);
  for (long i = 0; i < n; i++) {
    scanf("%ld", &a[i]);
    if (hash.find(a[i]) != hash.end())
      hash[a[i]].push_back(i);
    else {
      vector<long> v;
      v.push_back(i);
      hash[a[i]] = v;
    }
  }
  mi = hash.begin();
  while (mi != hash.end()) {
    if (mi->first > mi->second.size()) {
      long temp = mi->first;
      mi++;
      hash.erase(hash.find(temp));
    } else
      mi++;
  }
  long diff = r - l + 1, count = 0;
  for (long i = 0; i < m; i++) {
    scanf("%ld %ld", &l, &r);
    diff = r - l + 1, count = 0;
    mi = hash.begin();
    while (mi->first <= diff && mi != hash.end()) {
      vi1 = upper_bound(mi->second.begin(), mi->second.end(), r - 1);
      vi2 = lower_bound(mi->second.begin(), mi->second.end() - (mi->first - 1),
                        l - 1);
      long last = vi1 - mi->second.begin(), first = vi2 - mi->second.begin();
      if (last - first == mi->first) count++;
      mi++;
    }
    printf("%ld\n", count);
  }
  return 0;
}
