#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define MAX 2000000
#define MOD 1000000007
#define INF 1000000000

int main(){
  ll L,R;
  cin>>L>>R;
  vector<int> cnt(R-L+1,1);
  vector<ll> A(R-L+1);
  for(ll i=L;i<=R;i++){
    A[i-L]=i;
  }
  for(ll i=2;i<=10000000;i++){
    ll x=i*i;
    for(ll j=((L-1)/x+1)*x;j<=R;j+=x){
      cnt[j-L]=0;
    }
    for(ll j=((L-1)/i+1)*i;j<=R;j+=i){
      while(A[j-L]%i==0){
        A[j-L]/=i;
      }
    }
  }
  for(ll i=L;i<=R;i++){
    ll left=0;
    ll right=1000000001;
    while(left+1<right){
      ll x=(left+right)/2;
      if(x*x<=A[i-L]){
        left=x;
      }else{
        right=x;
      }
    }
    if(left*left==A[i-L]&&left>1){
      cnt[i-L]=0;
    }
  }

  int ans=0;
  for(ll i=L;i<=R;i++){
    ans+=cnt[i-L];
  }
  cout<<ans<<'\n';
}