#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <iostream>
using namespace std;
const int N = 3000010;
long long  phi[N];
void solve()
{
    memset( phi , 0 ,sizeof phi );
    phi[1] = 1 ;
    for( int i = 2 ; i < N ; ++i ){
        if( !phi[i] ){
            for( int j = i ; j < N ; j += i ){
                if( !phi[j] ) phi[j] = j ;
                phi[j] = phi[j] / i * ( i - 1 );
            }
        }
    }
}

int main()
{
    ios::sync_with_stdio(false);
    solve();
    for( int i = 2 ; i < N ; ++i ){
        phi[i] += phi[i-1] ;
    }
    int a , b ;
    while( cin >> a >> b  ){
        cout << phi[b] - phi[ a - 1 ] <<endl;
    }
}