#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000001

bool check(long long n){
	long long ok = 1,ng = 1000000001;
	while(ng-ok>1LL){
		long long mid = (ok+ng)/2;
		if(mid*mid <= n)ok = mid;
		else ng = mid;
	}
	if(ok!=1 && ok*ok==n)return true;
	return false;
}

int main(){
	
	long long L,R;
	cin>>L>>R;
	
	vector<long long> A(R-L+1);
	rep(i,A.size())A[i] = L+i;
	
	vector<long long> B = A;
	vector<bool> t(A.size(),false);
	
	for(long long i=2;i<=1000005;i++){
		long long te = (L+i-1)/i;
		te *= i;
		for(long long j=te;j<=R;j+=i){
			if(A[j-L]%(i*i)==0)t[j-L] = true;
			while(B[j-L]%i==0)B[j-L]/=i;
		}
	}
	int ans = 0;
	rep(i,B.size()){
		if(t[i])continue;
		if(check(B[i]))continue;
		ans++;
	}
	
	cout<<ans<<endl;
	
	return 0;
}