code nguồn(py thì tle :)) ):

def sang():
    f[0]=False
    f[1]=False
    for i in range(2,int(1000000**0.5)+1):
        if f[i]:
            for j in range(i*i,1000001,i):
                f[j]=False

l,r=map(int,input().split())
f=[True]*(1000001)
sang()
d=0
for i in range(1,r+1):
    if f[i]:
        if i*i>r:
            break
        else:
            for j in range(i+1,r+1):
                if f[j]:
                    if i*j>r:
                        break
                    else:
                        if i*j>=l:
                            d+=1
for i in range(2,int(r**(1/3))+1):
    if f[i] and i**3<=r and i**3>=l:
        d+=1
print(d)

code từ py->cpp(đã ac):

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

const int MAXN = 10000001;
vector<bool> f(MAXN, true);

void sang() {
    f[0] = false;
    f[1] = false;
    for (int i = 2; i <= sqrt(MAXN - 1); ++i) {
        if (f[i]) {
            for (int j = i * i; j < MAXN; j += i) {
                f[j] = false;
            }
        }
    }
}

int main() {
    int l, r;
    cin >> l >> r;
    sang();
    
    int d = 0;
    for (int i = 1; i <= r; ++i) {
        if (f[i]) {
            if (i * i > r) {
                break;
            } else {
                for (int j = i + 1; j <= r; ++j) {
                    if (f[j]) {
                        if (i * j > r) {
                            break;
                        } else {
                            if (i * j >= l) {
                                ++d;
                            }
                        }
                    }
                }
            }
        }
    }

    for (int i = 2; i <= cbrt(r); ++i) {
        if (f[i] && pow(i, 3) <= r && pow(i, 3) >= l) {
            ++d;
        }
    }

    cout << d << endl;
    return 0;
}