#include <bits/stdc++.h>
using namespace std;
long long int arr[5000001];
long long int a[5000001];
long long int b[5000001];
void count() {
  for (long long int i = 2; i < 5000001; i++) {
    if (arr[i] == 0) {
      for (long long int j = i * i; j < 5000001; j += i) {
        if (arr[j] == 0) {
          arr[j] = i;
        }
      }
    }
  }
}
void countPrimeNumbers() {
  a[1] = 0;
  for (long long int i = 2; i < 5000001; i++) {
    long long int k;
    if (arr[i] != 0) {
      long long int j = i;
      long long int res = 0;
      while (true) {
        k = arr[j];
        res++;
        if (k == 0) break;
        j = j / k;
      }
      a[i] = res;
    } else {
      a[i] = 1;
    }
  }
}
int main() {
  long long int t;
  scanf("%lld", &t);
  for (long long int i = 0; i < 5000001; i++) {
    arr[i] = 0;
  }
  count();
  countPrimeNumbers();
  b[1] = 0;
  for (long long int i = 2; i < 5000001; i++) {
    b[i] = b[i - 1] + a[i];
  }
  long long int a1;
  long long int b1;
  for (long long int i = 0; i < t; i++) {
    scanf("%lld", &a1);
    scanf("%lld", &b1);
    long long int num = b[a1] - b[b1];
    printf("%lld\n", num);
  }
  return 0;
}
