#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

vector<bool> sieve(int n){
    vector<bool> ret(n+1,true);
    ret[0]=false;
    if(n>0) ret[1]=false;
    for(int i=2;i*i<=n;i++){
        if(!ret[i]) continue;
        for(int j=i*2;j<=n;j+=i) ret[j]=false;
    }
    return ret;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll l,r;cin>>l>>r;
    vector<bool> v(r+1,true);
    for(int i=r;i>=l;i--){
        for(int j=1;j*j<=i;j++){
            if(i%j) continue;
            int x=j,y=i/j;
            if(x!=i){
                if(l<=x and x<=r and !v[x]) v[i]=false;
                else v[x]=false;
            }
            if(y!=i and y!=x){
                if(l<=y and y<=r and !v[y]) v[i]=false;
                else v[y]=false;
            }
        }
    }


    int cnt=0;
    for(int i=l;i<=r;i++){
        // cout<<i<<" : "<<v[i]<<endl;
        cnt+=v[i];
    }
    cout<<cnt-1<<endl;
    return 0;
}