#include <bits/stdc++.h>
using namespace std;
const long double pi = 3.1415926535897932384626433;
const int mod = 1e9 + 7;
const int inf = 1e18;
vector<long long> nof(5000001);
long long dhoni[5000007];
void pre2() { memset(dhoni, 0, sizeof(dhoni)); }
void erat1() {
  pre2();
  dhoni[0] = dhoni[1] = -1;
  for (long long i = 2; i <= 5000000; i++) {
    if (!dhoni[i])
      for (long long j = i; j <= 5000000; j += i) {
        if (!dhoni[j]) dhoni[j] = i;
      }
  }
}
void pre() {
  erat1();
  nof[1] = 0;
  for (long long i = 2; i <= 5000000; i++) {
    nof[i] = (nof[i / dhoni[i]] + 1);
  }
  for (long long i = 2; i <= 5000000; i++) {
    nof[i] += nof[i - 1];
  }
}
long long ans(long long a, long long b) { return nof[a] - nof[b]; }
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  pre();
  long long t;
  cin >> t;
  while (t--) {
    long long a, b;
    cin >> a >> b;
    cout << ans(a, b) << "\n";
    ;
  }
}
