giúp mình làm bài này bằng c++ với ạ

// carot15

#include<bits/stdc++.h>

using namespace std;

#define ll long long

const ll nmax=1e7+5;

bool f[nmax];

int main(){  

ll l,r,ans=0;

cin>>l>>r;

for (int i=2;i*i<=r;i++)

   if (!f[i])

      for (int e=i*i;e<=r;e+=i) f[e]=1;

for (int i=2;i<=r;i++)

   if (!f[i]) {

      if (i>=l) ans+=max(0LL,(r/i-(l-1)/i-1)*i);

      else ans+=(r/i-(l-1)/i)*i;

   }

cout<<ans;

}

#include <bits/stdc++.h>
#define ll long long 
using namespace std;
const int h = 10000000;
bool kt[h+7] = {false};
ll l, r, n = 0, a[h+7], res = 0;
void sieve(){
    kt[0] = true; kt[1] = true;
    for ( int i = 2; i * i <= h; i++ ){
        if ( kt[i] == false )
        for ( int j = i * i; j <= h; j += i ) kt[j] = true;
    }
    for ( int i = 2; i < h; i++ ){
        if ( !kt[i] ){
            for ( int j = 2 * i; j <= h ; j += i ) a[j] += i;
        } 
    }
}
int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    sieve();
    cin >> l >> r;
    for ( int i = l; i <= r; i++ ) res += a[i];
    cout << res;
}