#include <bits/stdc++.h>
using namespace std;
template <class T>
int getbit(T s, int i) {
  return (s >> i) & 1;
}
template <class T>
T onbit(T s, int i) {
  return s | (T(1) << i);
}
template <class T>
T offbit(T s, int i) {
  return s & (~(T(1) << i));
}
template <class T>
int cntbit(T s) {
  return __builtin_popcount(s);
}
template <class T>
T gcd(T a, T b) {
  T r;
  while (b != 0) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
bool isprime[5000005];
int back[5000005];
long long f[5000005];
void init() {
  memset(isprime, 1, sizeof(isprime));
  isprime[1] = 0;
  for (int i = 2; i < 5000005; i++)
    if (isprime[i]) {
      back[i] = i;
      for (int j = i + i; j < 5000005; j += i) {
        isprime[j] = 0;
        back[j] = i;
      }
    }
  f[1] = 0;
  for (int i = 2; i < 5000005; i++) {
    f[i] = f[i / back[i]] + 1;
  }
  for (int i = 2; i < 5000005; i++) {
    f[i] += f[i - 1];
  }
}
int test, a, b;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  init();
  cin >> test;
  for (int itest = 0; itest < (test); ++itest) {
    cin >> a >> b;
    cout << f[a] - f[b] << "\n";
  }
  return 0;
}
