#danglam228

#include<bits/stdc++.h>
#define ll long long 
using namespace std;
ll a,b,d=0;
ll tt(ll n){
    ll kq=1;
    for(int i=2;1LL*i*i<=n;i++){
        ll k=0;
        while(n%i==0){
             k++;
             n=n/i;
        }
        kq=kq*(k+1);
    }
    if(n>1) kq=kq*2;
    return kq;
}
int main(){
    cin>>a>>b;
    ll m=round(sqrt(a));
    ll n=round(sqrt(b));
    for(int i=m;i<=n;i++){
        if(tt(i)==3){
            d++;
        }
    }
    cout<<d;
}