#include <bits/stdc++.h>
using namespace std;
int main(){
    long long L, R;
    cin >> L >> R;
    vector<int> fac(1000010);
    iota(fac.begin(), fac.end(), 0);
    for(int i = 2; i < 1000010; i++){
        if(fac[i] != i) continue;
        for(int j = i * 2; j < 1000010; j += i){
            fac[j] = i;
        }
    }
    vector<long long> t(R - L + 1);
    vector<long long> temp;
    vector<int> num(R - L + 1);
    iota(t.begin(), t.end(), L);
    for(int i = 2; i <= 1000010; i++){
        if(fac[i] != i) continue;
        for(long long j = (L + i - 1) / i * i; j <= R; j += i){
            int cnt = 0;
            while(t[j - L] % i == 0){
                t[j - L] /= i;
                cnt++;
            }
            if(cnt > 1) num[j - L] = -1;
        }
    }
    for(int i = 0; i < R - L + 1; i++){
        if(num[i] == 0) temp.push_back(L + i);
    }
    int ans = temp.size();
    for(int i = 0; i < (int)temp.size(); i++){
        long long ub = 1000000000, lb = 0;
        while(ub - lb > 1){
            long long mid = (ub + lb) / 2;
            if(mid * mid >= t[temp[i] - L]) ub = mid;
            else lb = mid;
        }
        if(ub != 1 && ub * ub == t[i]) ans--;
    }
    cout << ans << endl;
}