#include <iostream>
#include <bitset>
#include "testlib.h"
using namespace std;
typedef long long ll;
const int MAX=1000010;
bitset<MAX> isprime;
void sieve(){
	for(int i=3; i<MAX; i++, i++) isprime[i]=1;
	isprime[2]=1;
	for(int i=3; i<MAX; i++){
		if(isprime[i]){
			for(int j=(i<<1); j<MAX; j+=i) isprime[j]=0;
		}
	}
}
ll x[MAX];
bitset<MAX> sqf;
const ll MAXD=1000000;
const ll MAXR=1000000000000000000ll;
int main(int argc, char* argv[]){
    registerValidation(argc, argv);
    ll l=inf.readLong(1ll, MAXR);
    inf.readSpace();
    ll r=inf.readLong(1ll, MAXR);
    ensure(l<=r && r-l<=MAXD);
    inf.readEoln();
    inf.readEof();
    
    sieve();
	for(ll i=l; i<=r; i++){
		x[i-l]=i;
		sqf[i-l]=1;
	}
	for(ll p=2; p<MAX; p++){
		if(!isprime[p]) continue;
		for(ll i=(l+p-1)/p*p; i<=r; i+=p){
			int e=0;
			while(x[i-l]%p==0){
				x[i-l]/=p;
				e++;
			}
			if(e>1) sqf[i-l]=0;
		}
	}
	int ans=0;
	for(ll i=l; i<=r; i++){
		if(!sqf[i-l]) continue;
        if(x[i-l]==1){
            ans++;
            continue;
        }
		ll xl=1, xr=1e9+7;
		while(xr-xl>1){
			ll xm=(xl+xr)/2;
			if(xm*xm<=x[i-l]) xl=xm;
			else xr=xm;
		}
		if(xl*xl!=x[i-l]) ans++;
	}
	cout<<ans<<endl;
    return 0;
}