#ifdef NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(i64 i=0; i<i64(n); i++)
const i64 INF = 1001001001001001001;
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
using namespace std;


#include <cassert>

namespace nachia{

namespace internal{

// mod 2^64
constexpr unsigned long long PowerOfULongLong(unsigned long long a, unsigned long long i){
    unsigned long long res = 1;
    while(i){ if(i&1){ res *= a; } i /= 2; a *= a; }
    return res;
}

}

unsigned long long FloorOfKthRoot(unsigned long long real, unsigned long long k){
    using u64 = unsigned long long;
    assert(k != 0);
    if(real <= 1) return real;
    if(k >= 64) return 1;
    if(k == 1) return real;
    struct Precalc{
        // a^i <= x
        static constexpr bool lesseq(u64 a, int i, u64 x) {
            if (a == 0) return true;
            for(int j=0; j<i; j++) x /= a;
            return x >= 1;
        }
        unsigned long long BORDER[64];
        constexpr Precalc() : BORDER() {
            for (int idx = 2; idx <= 63; idx++) {
                u64 l = 0, r = 1ull << 33;
                while (l + 1 < r) {
                    u64 m = (l + r) / 2;
                    if (lesseq(m, idx, ~0ull)) l = m;
                    else r = m;
                }
                BORDER[idx] = r;
            }
        };
    };
    constexpr Precalc precalc;
    u64 l = 0, r = precalc.BORDER[k];
    if(real < r) r = real;
    while (l + 1 < r) {
        u64 m = (l + r) / 2;
        if(internal::PowerOfULongLong(m, k) <= real) l = m;
        else r = m;
    }
    return l;
}

unsigned long long CeilOfKthRoot(unsigned long long real, unsigned long long k){
    if(real <= 1) return real;
    if(k >= 64) return 2;
    if(k == 1) return real;
    unsigned long long x = FloorOfKthRoot(real, k);
    if(internal::PowerOfULongLong(x, k) != real) x++;
    return x;
}

} // namespace nachia

void testcase(){
    i64 L, R; cin >> L >> R;
    vector<i64> X(R-L+1);
    rep(i,X.size()) X[i] = L+i;
    vector<i64> sieve(1000001, 1);
    for(i64 p=2; p<=1000000; p++) if(sieve[p]){
        for(i64 q=p*p; q<sieve.size(); q+=p) sieve[q] = 0;
        for(i64 q=(L+p-1)/p*p; q<=R; q+=p) if(X[q-L] != 0){
            if(X[q-L] % (p*p) == 0) X[q-L] = 0;
            else if(X[q-L] % p == 0) X[q-L] /= p;
        }
    }
    i64 ans = 0;
    for(i64 x : X) if(x != 0){
        i64 y = x == 1 ? 0 : nachia::FloorOfKthRoot(x, 2);
        if(y*y != x) ans += 1;
    }
    cout << ans << "\n";
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    testcase();
    return 0;
}