#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100010, MAXC = 500;
int can[MAXC], c = 0;
int n, m, a[MAXN], b[MAXN];
int t[MAXN][MAXC];
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> a[i];
  memcpy(b, a, sizeof(b));
  sort(b, b + n);
  for (int i = 0; i < n; i++) {
    int end = i;
    while (b[end] == b[i]) end++;
    if (end - i >= b[i]) can[c++] = b[i];
    i = end - 1;
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < c; j++) {
      t[i + 1][j] = t[i][j];
      if (a[i] == can[j]) t[i + 1][j]++;
    }
  }
  int l, r;
  for (int i = 0; i < m; i++) {
    cin >> l >> r;
    int ans = 0;
    for (int j = 0; j < c; j++)
      if (t[r][j] - t[l - 1][j] == can[j]) ans++;
    cout << ans << endl;
  }
  return 0;
}
