#include <bits/stdc++.h>
using namespace std;
const int maxN = 5e6 + 100;
const int maxn = 5e6 + 100;
int p[maxN], fac[maxN], a[maxN], b[maxN], t;
int logarithm(int x, int z) {
  int m = 1, y = 0;
  while (x % (m * z) == 0) {
    y++;
    m *= z;
  }
  return y;
}
void gharbal() {
  for (int i = 2; i < maxn; i++) {
    if (p[i] == 0) {
      int q = i;
      while (q < maxn) {
        p[q] += logarithm(q, i);
        q += i;
      }
    }
  }
}
void make_fac() {
  fac[0] = 0;
  for (int i = 0; i < maxn; i++) fac[i] = fac[i - 1] + p[i];
}
void input() {
  cin >> t;
  for (int i = 0; i < t; i++) cin >> a[i] >> b[i];
}
void output() {
  for (int i = 0; i < t; i++) {
    cout << fac[a[i]] - fac[b[i]] << "\n";
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  input();
  gharbal();
  make_fac();
  output();
}
