#include <iostream>
#include <bits/stdc++.h>
#include <map>
#include <list>
#include <utility>
#include <algorithm>
#include <vector>
#define INF 10000000000
#define ll long long int
#define pb push_back
#define mp make_pair
#define FOR(i, n) for (int i = 0; i < n; i++)
#define FORR(i, a, b) for (int i = a; i < b; i++)
using namespace std;

bool isprime[5000009];
int dp[5000009], minfact[5000009];
int fact[5000009]; // sum of factors of factorial till i

void sieve_fun()
{
    for (int i = 0; i < 5000009; i++)
    {
        isprime[i] = true;
    }
    isprime[0] = isprime[1] = false;
    minfact[0] = 0;
    minfact[1] = 0;
    minfact[2] = 2;

    for (int i = 3; i < 5000009; i += 2)
    {
        if (isprime[i] == true)
        {
            minfact[i] = i;
            for (int j = i; (((ll)j) * ((ll)i)) < 5000009; j += 2)
            {
                isprime[i * j] = false;
                minfact[i * j] = i;
            }
        }
    }

    return;
}

void dp_fun() // dp will store sum of prime factors of num
{
    for (int i = 2; i < 5000009; i++)
    {
        if (i % 2 == 0)
        {
            dp[i] = dp[i / 2] + 1;
        }
        else
        {
            dp[i] = dp[i / minfact[i]] + 1;
        }
    }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    sieve_fun();

    int t;
    cin >> t;

    memset(dp, -1, sizeof(dp));
    dp[1] = 0, dp[0] = 0;
    dp_fun();

    fact[0] = fact[1] = 0;
    for (int i = 2; i < 5000009; i++)
    {
        fact[i] = fact[i - 1] + dp[i];
    }

    FOR(j, t)
    {
        int a, b;
        cin >> a >> b;

        cout << fact[a] - fact[b] << endl;
    }
    return 0;
}