#include <iostream>
using namespace std;
int main() {
int a, b;
cin>>a>>b;
if (a%2!= 0) {
a++;
}
if (a%3!=0) {
a+=(3-a%3);
}
for (int i=a;i<=b;i+=6) {
cout<<i<<" ";
}
cout<<endl;
return 0;
}

$#doanthevu$

Code C++:

#include <bits/stdc++.h>
using namespace std;
define ll long long
const ll maxN = 1e5 + 1;
ll a, b, dem=0;
void hoidap()
{
    cin >> a >> b;
}
void Solve()
{
    if (a % 2 != 0) a++;
    while (a <= b)
    {
        if (a % 3 == 0) dem++;
        a += 2;
    }
    cout << dem;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    hoidap();
    Solve();
    return 0;
}