#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    ll L, R;
    cin >> L >> R;
    set<ll> st;
    rep(i, 0, R - L + 1) st.insert(i + L);
    rep(i, 2, 1e6) {
        ll x = 1LL * i * i;
        for (ll j = max(L / x * x, x); j <= R; j += x) {
            //cout << j << endl;
            st.erase(j);
            //for (auto k : st) cout << k << " "; cout << endl;
        }
    }
    rep(i, 1, 1e6) {
        ll x = sqrt(R / i);
        if (x == 1) continue;
        st.erase(x * x * i);
    }
    cout << st.size() << endl;
}