#include <bits/stdc++.h>
using namespace std;
//const long nPrime = 1000000007;
//const long nPrime = 998244353;
//n以下の素数列
void LF_Prime_Sequence(const long &n, vector<long> &viPrime){
    if(n < 2){
        return;
    }
    viPrime.clear();
    vector<char> aiType(n + 1,0);
    long iTmp = 2;
    while(true){
        if(iTmp * iTmp > n){
            break;
        }
        for(long j = iTmp; j * iTmp <= n; j++){
            aiType[j * iTmp] = 1;
        }
        for(long j = iTmp+1; j <= n; j++){
            if(aiType[j] == 0){
               iTmp = j;
               break;
            }
        }
    }
    for (long i = 2; i <= n; i++){
        if(aiType[i] == 0){
            viPrime.push_back(i);
        }
    }
    return;
}
int main() {
    vector<long> viPrime;
    LF_Prime_Sequence(40000000,viPrime);
    
    long l,r;
    cin >> l >> r;
    vector<long> viOK(r-l+1,1);
    for(long i = 0; viPrime[i] < 1000; i++){
        long iTmp = r/(viPrime[i]*viPrime[i]);
        iTmp *= (viPrime[i]*viPrime[i]);
        iTmp -= l;
        for(; iTmp >= 0; iTmp -= (viPrime[i]*viPrime[i])){
            viOK[iTmp] = 0;
        }
    }
    for(long i = 0; i < viPrime.size(); i++){
        long iTmp = r/(viPrime[i]*viPrime[i]);
        iTmp *= (viPrime[i]*viPrime[i]);
        iTmp -= l;
        if(iTmp >= 0){
            viOK[iTmp] = 0;
        }
    }
    
    for(long i = 0; i < r-l+1; i++){
        if(viOK[i] == 0){
            continue;
        }
        long nThis = i+l;
        for(long j = 0; viPrime[j] < 1000; j++){
            while(nThis % viPrime[j] == 0){
                nThis /= viPrime[j];
            }
            if(nThis < 1e15){
                break;
            }
        }
        if(nThis < 1e15){
            continue;
        }
        
        long nSqrt = long(sqrt(double(nThis)));
        if(nSqrt*nSqrt != nThis){
            continue;
        }
        bool bPrime = true;
        for(long j = 0; viPrime[j] < 10000; j++){
            if(nSqrt%viPrime[j]==0){
                bPrime = false;
                break;
            }
        }
        if(bPrime){
           viOK[i] = 0; 
        }
    }
    
    long nAns = 0;
    for(long i = 0; i < r-l+1; i++){
        nAns += viOK[i];
    }
    
    cout << nAns << endl;
    return 0;
}