#include <bits/stdc++.h>
using namespace std;
using u64 = uint64_t;

constexpr int rt = 2e6, rt2 = (u64)1e18 / rt / rt, width = 1e6 + 1;
bool isprime[rt + 1], ans_[width];
void sieve_of_atkin(){
    constexpr int N = 2e6, sqrtN = 1414;
    int n;
    for(int z = 1; z <= 5; z += 4){
        for(int y = z; y <= sqrtN; y += 6){
            for(int x = 1; x <= sqrtN && (n = 4*x*x+y*y) <= N; ++x)
                isprime[n] = !isprime[n];
            for(int x = y+1; x <= sqrtN && (n = 3*x*x-y*y) <= N; x += 2)
                isprime[n] = !isprime[n];
        }
    }
    for(int z = 2; z <= 4; z += 2){
        for(int y = z; y <= sqrtN; y += 6){
            for(int x = 1; x <= sqrtN && (n = 3*x*x+y*y) <= N; x += 2)
                isprime[n] = !isprime[n];
            for(int x = y+1; x <= sqrtN && (n = 3*x*x-y*y) <= N; x += 2)
                isprime[n] = !isprime[n];
        }
    }
    for(int y = 3; y <= sqrtN; y += 6){
        for(int z = 1; z <= 2; ++z){
            for(int x = z; x <= sqrtN && (n = 4*x*x+y*y) <= N; x += 3)
                isprime[n] = !isprime[n];
        }
    }
    for(int n = 5; n <= sqrtN; ++n)
        if(isprime[n])
            for(int k = n*n; k <= N; k+=n*n)
                isprime[k] = false;
    isprime[2] = isprime[3] = true;
}
u64 ceilk(u64 n, u64 k){
    const u64 r = n % k;
    return r ? n + k - r : n;
}
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    sieve_of_atkin();
    u64 L = 1e18 - 1e6, R = 1e18;
    cin >> L >> R;
    auto ans = ans_ - L;
    for(int i = 2; i <= rt; i++) if(isprime[i]){
        const u64 p = u64(i) * i;
        for(u64 i = ceilk(L, p); i <= R; i += p) ans[i] = true;
    }
    for(int k = 1; k <= rt2; k++){
        int i = sqrt(R / k);
        if(u64(k) * (i + 1) * (i + 1) <= R) i++;
        if(i > 1 && u64(k) * i * i >= L) ans[u64(k) * i * i] = true;
    }
    cout << count(ans_, ans_ + (R - L + 1), false) << endl;
}