// #pragma GCC optimize ("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target ("avx,avx2,fma")
#include <bits/stdc++.h>

#define rep(i, a, b) for(int i = (a); i <= (b); i ++)
using std::cin, std::cout, std::cerr;
using ll = long long;

ll Sqrt(ll x) {
    ll s = std::sqrt(x);
    while((s + 1) * (s + 1) <= x)
        s ++;
    while(s * s > x)
        s --;
    return s;
}

int main() {
    std::ios::sync_with_stdio(false);
    ll l, r; cin >> l >> r;
    ll n = 1e6;
    std::vector<ll> a(r - l + 1);
    std::vector<bool> squarefree(r - l + 1, true);
    std::iota(a.begin(), a.end(), l);

    for(ll i = 2; i <= n; i ++) {
        for(ll j = (l + i * i - 1) / (i * i) * (i * i); j <= r; j += i * i)
            squarefree[j - l] = false;
        for(ll j = (l + i - 1) / i * i; j <= r; j += i)
            while(a[j - l] % i == 0)
                a[j - l] /= i;
    }

    for(ll i = l; i <= r; i ++) if(a[i - l] > 1) {
        ll s = Sqrt(a[i - l]);
        if(s * s == a[i - l])
            squarefree[i - l] = false;
    }

    cout << std::ranges::count(squarefree, true) << '\n';
}