#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;}

struct UnionFind{
    vector<int> par;
    vector<int> siz;
    int c;//親の個数(グループ数)
    void init(int n){
        c=n;
        for(int i=0;i<n;i++){
            par.push_back(i);
            siz.push_back(1);
        }
    }
    UnionFind(int n){
        init(n);
    }
    int root(int x){
        //根を返す
        return(par[x]==x?x:(par[x]=root(par[x])));
    }
    bool sameParent(int x,int y){
        return(root(x)==root(y));
    }
    void unite(int x, int y){
        x=root(x);y=root(y);
        if(x==y)    return;
        if(siz[x]<siz[y]) swap(x,y);
        siz[x] += siz[y];par[y]=x;c--;
    }
    int size(int x){
        return siz[root(x)];
    }
};

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll l,r;cin>>l>>r;
    UnionFind uf(r+1);
    for(int i=l;i<=r;i++){
        for(int j=1;j*j<=i;j++){
            if(i%j) continue;
            if(l<=j and j<=r) uf.unite(i,j);
            if(l<=i/j and i/j<=r) uf.unite(i,i/j);
        }
    }
    int ans=0;
    for(int i=l;i<=r;i++)if(uf.root(i)==i)ans++;
    ans--;
    cout<<ans<<endl;
    return 0;
}