#include <bits/stdc++.h>
using namespace std;
vector<long long int> prime(5000001, 0);
vector<long long int> ans(5000001, 0);
void sieve(long long int n) {
  for (long long int i = 2; i * i <= n; i++) {
    if (prime[i] == 0) {
      for (long long int j = i * i; j <= n; j += i) {
        if (prime[j] == 0) prime[j] = i;
      }
    }
  }
  for (long long int i = 2; i <= n; i++) {
    if (prime[i] == 0) prime[i] = i;
  }
}
long long int prime_factors(long long int f) {
  long long int c = 0;
  while (f != 1) {
    f = f / prime[f];
    c++;
  }
  return c;
}
void pre() {
  for (long long int i = 1; i <= 5000000; i++)
    ans[i] = ans[i - 1] + prime_factors(i);
}
void solve() {
  long long int a, b;
  cin >> a >> b;
  cout << ans[a] - ans[b] << "\n";
}
void c_p_c() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
int32_t main() {
  c_p_c();
  sieve(5000000);
  pre();
  long long int t;
  cin >> t;
  while (t--) solve();
  return 0;
}
