#include <bits/stdc++.h>
using namespace std;
int fn[100010] = {0};
inline void upd(int i, int val) {
  for (int idx = i; idx <= 100010; idx += (idx & -idx)) fn[idx] += val;
}
inline int gg(int e) {
  int res = 0;
  for (int idx = e; idx; idx -= (idx & -idx)) res += fn[idx];
  return res;
}
int in[100010];
vector<pair<int, int> > qr[100010];
vector<int> ans;
vector<int> aqq[100010];
int main() {
  int n, m;
  cin >> n >> m;
  ans.resize(m);
  for (int i = 1; i < n + 1; i += 1) {
    cin >> in[i];
    if (in[i] > n) in[i] = -1;
  }
  for (int i = 0; i < m; i += 1) {
    int s, e;
    cin >> s >> e;
    qr[e].push_back(make_pair(i, s));
  }
  long long res = 0;
  for (int i = 1; i < n + 1; i += 1) {
    int tt = in[i];
    if (in[i] != -1) {
      aqq[tt].push_back(i);
      if (aqq[tt].size() >= tt) upd(aqq[tt][aqq[tt].size() - tt], 1);
      if (aqq[tt].size() > tt) upd(aqq[tt][aqq[tt].size() - tt - 1], -2);
      if (aqq[tt].size() > tt + 1) upd(aqq[tt][aqq[tt].size() - tt - 2], 1);
    }
    for (int j = 0; j < qr[i].size(); j += 1) {
      int s = qr[i][j].second;
      int ind = qr[i][j].first;
      ans[ind] = gg(i) - gg(s - 1);
    }
  }
  for (int i = 0; i < m; i += 1) cout << ans[i] << endl;
  return 0;
}
