#include <bits/stdc++.h>
using namespace std;
int a[100005];
int mp[100005];
int ans[100005], answer;
int sz;
struct data {
  int l, r, ind;
} Q[100005];
bool cmp(data a, data b) {
  if (a.l / sz == b.l / sz) return a.r < b.r;
  return a.l / sz < b.l / sz;
}
void add(int index) {
  mp[a[index]]++;
  if (mp[a[index]] == a[index])
    answer++;
  else if (mp[a[index]] == 1 + a[index])
    answer--;
}
void rem(int index) {
  mp[a[index]]--;
  if (mp[a[index]] == a[index])
    answer++;
  else if (mp[a[index]] + 1 == a[index])
    answer--;
}
int main() {
  int t, n, i, j, cas = 1, q, l, r;
  answer = 0;
  scanf("%d%d", &n, &q);
  sz = sqrt(n);
  memset(mp, 0, sizeof mp);
  for (i = 1; i <= n; i++) {
    scanf("%d", a + i);
    if (a[i] > n) a[i] = -1;
  }
  for (i = 1; i <= q; i++) {
    scanf("%d%d", &Q[i].l, &Q[i].r);
    Q[i].ind = i;
  }
  sort(Q, Q + q, cmp);
  int s = 0, e = 0;
  for (i = 1; i <= q; i++) {
    l = Q[i].l, r = Q[i].r;
    while (s < l) {
      rem(s);
      s++;
    }
    while (s > l) {
      add(s - 1);
      s--;
    }
    while (e <= r) {
      add(e);
      e++;
    }
    while (e > r + 1) {
      rem(e - 1);
      e--;
    }
    ans[Q[i].ind] = answer;
  }
  for (i = 1; i <= q; i++) {
    printf("%d\n", ans[i]);
  }
}
