#include <bits/stdc++.h>
using namespace std;
int main(){
  long long L, R;
  cin >> L >> R;
  vector<bool> ok(R - L + 1, true);
  for (long long i = 2; i <= 2000000; i++){
    long long m = i * i;
    for (long long j = (L + m - 1) / m * m; j <= R; j += m){
      ok[j - L] = false;
    }
  }
  for (int j = 1; j <= 2000000; j++){
    long long a = sqrt(L / j);
    while (true){
      if (a * a * j > R){
        break;
      }
      if (a >= 2 && a * a * j >= L){
        ok[a * a * j - L] = false;
      }
      a++;
    }
  }
  int ans = 0;
  for (int i = 0; i <= R - L; i++){
    if (ok[i]){
      ans++;
    }
  }
  cout << ans << endl;
}