#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;

vector<bool> sieve_of_atkin(int N){
    vector<bool> isprime(N + 1);
    const int sqrtN = sqrt(N);
    int n;
    for(int z = 1; z <= 5; z += 4) for(int y = z; y <= sqrtN; y += 6){
        for(int x = 1; x <= sqrtN && (n = 4*x*x+y*y) <= N; ++x) isprime[n] = !isprime[n];
        for(int x = y+1; x <= sqrtN && (n = 3*x*x-y*y) <= N; x += 2) isprime[n] = !isprime[n];
    }
    for(int z = 2; z <= 4; z += 2) for(int y = z; y <= sqrtN; y += 6){
        for(int x = 1; x <= sqrtN && (n = 3*x*x+y*y) <= N; x += 2) isprime[n] = !isprime[n];
        for(int x = y+1; x <= sqrtN && (n = 3*x*x-y*y) <= N; x += 2) isprime[n] = !isprime[n];
    }
    for(int y = 3; y <= sqrtN; y += 6) for(int z = 1; z <= 2; ++z){
        for(int x = z; x <= sqrtN && (n = 4*x*x+y*y) <= N; x += 3) isprime[n] = !isprime[n];
    }
    for(int n = 5; n <= sqrtN; ++n) if(isprime[n]) for(int k = n*n; k <= N; k+=n*n) isprime[k] = false;
    isprime[2] = isprime[3] = true;
    return isprime;
}
vector<int> primes(int N){
    auto isprime = sieve_of_atkin(N);
    vector<int> ans;
    for(int i = 2; i <= N; i++) if(isprime[i]) ans.push_back(i);
    return ans;
}
constexpr ll siz = 3.2e6;
int main(){
    auto P = primes(siz);
    ll L = 1e18 - 1e6, R = 1e18;
cin >> L >> R;
    vector<char> A_(R - L + 1, 1);
    auto A = A_.begin() - L;
    for(ll p : P){
        p *= p;
        for(ll i = R - R % p; i >= L; i -= p) A[i] = 0;
    }
    for(ll k = 1; k <= (ll)1e18 / siz / siz; k++){
        const ll lo = max<ll>(siz, ceil(sqrt((ld)L / k))), hi = sqrtl(R / k);
        for(ll i = lo; i <= hi; i++) A[k * i * i] = 0;
    }
    cout << reduce(A_.begin(), A_.end(), 0) << endl;
}