#include <bits/stdc++.h>

using i32 = std::int32_t;
using u32 = std::uint32_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

class rep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { ++itr; }
        constexpr bool operator!=(const Iter& other) const noexcept { return itr != other.itr; }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr rep(const usize first, const usize last) noexcept : first(first), last(std::max(first, last)) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

constexpr u64 ceil_log2(const u64 x) {
    u64 e = 0;
    while (((u64)1 << e) < x) ++e;
    return e;
}

template <class F> class AutoReallocation {
    using R = typename decltype(std::declval<F>()((usize)0))::value_type;

    F func;
    mutable std::vector<R> data;

  public:
    explicit AutoReallocation(F&& f) : func(std::forward<F>(f)), data() {}

    void reserve(const usize size) const {
        if (data.size() < size) data = func(((usize)1 << ceil_log2(size)));
    }
    R operator[](const usize i) const {
        reserve(i + 1);
        return data[i];
    }
};

template <class F> decltype(auto) auto_realloc(F&& f) {
    using G = std::decay_t<F>;
    return AutoReallocation<G>(std::forward<G>(f));
}

struct PrimeSieve {
    static inline const auto min_prime = auto_realloc([](const usize n) {
        std::vector<usize> ret(n);
        std::iota(ret.begin(), ret.end(), (usize)0);
        std::vector<usize> list;
        for (const usize i : rep(2, n)) {
            if (ret[i] == i) list.push_back(i);
            for (const usize p : list) {
                if (p * i >= n || p > ret[i]) break;
                ret[p * i] = p;
            }
        }
        return ret;
    });
    static bool is_prime(const usize n) {
        if (n <= 1) return false;
        return min_prime[n] == n;
    }
    template <class T> static std::vector<std::pair<T, usize>> factorize(T x) {
        assert(x > 0);
        std::vector<std::pair<T, usize>> ret;
        while (x != 1) {
            const usize p = min_prime[x];
            ret.emplace_back((T)p, 0);
            while (min_prime[x] == p) {
                ret.back().second++;
                x /= p;
            }
        }
        return ret;
    }
};

template <class T> using Vec = std::vector<T>;

i64 isqrt(const i64 X) {
    if (X <= 1) {
        return X;
    }
    i64 ok = 0, ng = X;
    while (ng - ok > 1) {
        const i128 md = (ok + ng) / 2;
        (md * md > (i128)X ? ng : ok) = md;
    }
    return ok;
}

bool is_sq(const i64 x) {
    const i64 y = isqrt(x);
    return y != 1 and y * y == x;
}

void main_() {
    i64 L, R;
    std::cin >> L >> R;
    Vec<char> ok(R - L + 1, true);
    for (i64 k = 2; k <= 1000000; ++k) {
        const i64 x = k * k;
        for (i64 i = (L + x - 1) / x * x; i <= R; i += x) {
            ok[i - L] = false;
        }
    }
    for (i64 k = 1; k <= 1000000; ++k) {
        for (i64 i = (L + k - 1) / k * k; i <= R; i += k) {
            if (ok[i - L] and is_sq(i / k)) {
                ok[i - L] = false;
            }
        }
    }
    usize cnt = 0;
    for (const auto c : ok) {
        if (c) {
            cnt += 1;
        }
    }
    std::cout << cnt << '\n';
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    main_();
    return 0;
}