#include <bits/stdc++.h>
using namespace std;
unordered_map<long long, long long> mp;
struct node {
  long long l, r, id, blc;
};
node q[100005];
long long arr[100005];
long long ans[100005];
long long sum;
void add(long long x) {
  x = arr[x];
  if (mp[x] == x) {
    sum--;
  }
  mp[x]++;
  if (mp[x] == x) {
    sum++;
  }
}
void rem(long long x) {
  x = arr[x];
  if (mp[x] == x) sum--;
  mp[x]--;
  if (mp[x] == x) {
    sum++;
  }
}
bool comp(node a, node b) {
  if (a.blc != b.blc) {
    return a.blc < b.blc;
  }
  return a.r < b.r;
}
int main() {
  long long i, j, k, l, m, n, o;
  long long testcase;
  long long input, flag, tag;
  scanf("%lld", &n);
  scanf("%lld", &m);
  for (i = 1; i <= n; i++) scanf("%lld", &arr[i]);
  long long ssq = sqrt(n) + 5;
  for (i = 1; i <= m; i++) {
    scanf("%lld", &j);
    scanf("%lld", &k);
    q[i].l = j;
    q[i].r = k;
    q[i].id = i;
    q[i].blc = j / ssq;
  }
  sort(q + 1, q + 1 + m, comp);
  l = 1;
  long long r = 0;
  sum = 0;
  for (i = 1; i <= m; i++) {
    while (l > q[i].l) add(--l);
    while (r < q[i].r) add(++r);
    while (l < q[i].l) rem(l++);
    while (r > q[i].r) rem(r--);
    ans[q[i].id] = sum;
  }
  for (i = 1; i <= m; i++) {
    printf("%lld\n", ans[i]);
  }
}
