#include <bits/stdc++.h>
using namespace std;
int n = 5000001;
void okms() {
  vector<int> kk(n);
  kk[0] = 0, kk[1] = 0;
  for (int(i) = 2; i < n; ++i) kk[i] = 1;
  vector<bool> ch(n);
  for (int(i) = 0; i < n; ++i) ch[i] = true;
  ch[0] = 0, ch[1] = 0;
  vector<int> trr(n);
  for (int i = 2; i * i <= n - 1; i++) {
    if (ch[i]) {
      trr[i] = i;
      for (int j = i * i; j <= n - 1; j += i) {
        ch[j] = false;
        trr[j] = i;
      }
    }
  }
  for (int(i) = 2; i < n; ++i) {
    if (!ch[i]) {
      kk[i] = kk[trr[i]] + kk[i / trr[i]];
    }
  }
  vector<int> ans(n);
  for (int(i) = 1; i < n; ++i) ans[i] += ans[i - 1] + kk[i];
  int t;
  cin >> t;
  while (t--) {
    int a, b;
    cin >> a >> b;
    cout << ans[a] - ans[b] << '\n';
  }
  return;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int test;
  test = 1;
  while (test--) {
    okms();
  }
  return 0;
}
