#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define each(e, v) for(auto &e: v)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const int MOD = 1000000007;
//const int MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};

struct io_setup{
    io_setup(){
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout << fixed << setprecision(15);
    }
} io_setup;

int main(){
    ll L, R; cin >> L >> R;
    int K = R-L;
    vector<bool> ok(K+1, true);

    ll M = 1000000;

    rep2(i, 1, M){
        ll l = 1, r = inf; //(l,r]
        while(r-l > 1){
            ll m = (l+r)/2;
            ll t = m*m;
            if(t > (L-1)/i) r = m;
            else l = m;
        }

        for(ll t = r; t*t*i <= R; t++){
            ok[t*t*i-L] = false;
        }
    }
    
    vector<bool> ps(M+1, true);

    for(ll i = 2; i <= M; i++){
        if(!ps[i]) continue;
        for(ll t = ((L+i-1)/i)*i; t <= R; t += i){
            if(t%(i*i) == 0) ok[t-L] = false;
        }
        for(int j = i+i; j <= M; j += i){
            ps[j] = false;
        }
    }

    int ans = 0;
    rep(i, K+1){
        if(ok[i]) ans++;
    }

    cout << ans << '\n';
}