#include <bits/stdc++.h>
using namespace std;

#define all(a) (a).begin(), (a).end()
#define uniq(a) (a).erase(unique(all(a)), (a).end())
using ll = long long;
using ull = unsigned long long;
using vll = vector<ll>;
using pll = pair<ll, ll>;
ull bit(int n) { return 1ull << n; }
template <typename T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
constexpr double PI = 3.1415926535897932384626433832795028;
constexpr ll DY[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
constexpr ll DX[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
ll sign(ll a) { return (a > 0) - (a < 0); }
ll cdiv(ll a, ll b) { return (a - 1 + b) / b; }
template <typename T> T sq(const T &a) { return a * a; }
template <typename T, typename U> bool chmax(T &a, const U &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <typename T, typename U> bool chmin(T &a, const U &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &a) {
    os << "(" << a.first << ", " << a.second << ")";
    return os;
}
template <typename T, typename U, typename V> ostream &operator<<(ostream &os, const tuple<T, U, V> &a) {
    auto [t, u, v] = a;
    os << "(" << t << ", " << u << ", " << v << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); itr++) { os << *itr << (next(itr) != a.end() ? ", " : ""); }
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); itr++) { os << *itr << (next(itr) != a.end() ? ", " : ""); }
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) { os << *itr << (next(itr) != a.end() ? ", " : ""); }
    os << "}";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) { os << *itr << (next(itr) != a.end() ? ", " : ""); }
    os << "}";
    return os;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const map<T, U> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) { os << *itr << (next(itr) != a.end() ? ", " : ""); }
    os << "}";
    return os;
}
struct setup {
    static constexpr ll PREC = 20;
    setup() {
        cout << fixed << setprecision(PREC);
        cerr << fixed << setprecision(PREC);
    };
} setup;

#ifdef ONLINE_JUDGE
#define dump(...) (void(0))
#else
void debug() { cerr << endl; }
template <typename Head, typename... Tail> void debug(Head &&head, Tail &&... tail) {
    cerr << head;
    if (sizeof...(Tail)) cerr << ", ";
    debug(tail...);
}
#define dump(...) cerr << __LINE__ << ": " << #__VA_ARGS__ << " = ", debug(__VA_ARGS__)
#endif

struct rep {
    struct itr {
        int v;
        itr(int v) : v(v) {}
        void operator++() { ++v; }
        int operator*() const { return v; }
        bool operator!=(const itr &i) const { return v != i.v; }
    };
    int l, r;
    rep(int r) : l(0), r(r) {}
    rep(int l, int r) : l(l), r(r) {}
    itr begin() const { return l; };
    itr end() const { return r; };
};
struct per {
    struct itr {
        int v;
        itr(int v) : v(v) {}
        void operator++() { --v; }
        int operator*() const { return v; }
        bool operator!=(const itr &i) const { return v != i.v; }
    };
    int l, r;
    per(int r) : l(0), r(r) {}
    per(int l, int r) : l(l), r(r) {}
    itr begin() const { return r - 1; };
    itr end() const { return l - 1; };
};
template <typename F> long long discrete_binary_search(long long ok, long long ng, F is_ok) {
    while (abs(ok - ng) > 1) {
        long long mid = (ok + ng) / 2;
        (is_ok(mid) ? ok : ng) = mid;
    }
    return ok;
}
int main() {
    ll l, r;
    cin >> l >> r;
    vll ng(r - l + 1);
    auto start = [&](ll x) -> ll { return l + (x - l % x) % x; };
    for (ll i : rep(1, 1e6 + 1)) {
        for (ll j = start(i); j <= r; j += i) {
            ll y = j / i;
            ll rt = discrete_binary_search(1, y, [&](ll rt) -> bool { return rt * rt <= y; });
            if (rt != 1 && rt * rt == y) ng[j - l] = 1;
        }
    }
    cout << r - l + 1 - accumulate(all(ng), 0ll) << endl;
}