C# The While Loop 15.2 Practice Calculating Range

Question

So I used the following code to get through the practice question, but is there a more logical way of writing this? I feel like I kinda cheated because I changed the initialization of res to 2, from 1. Thanks for the feedback.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SoloLearn
{
class Program
{
static void Main(string[] args)
{
int num = Convert.ToInt32(Console.ReadLine());
int res = 2;

while(res <= num) {
Console.WriteLine(res);
res+=2;
}
}
}
}

Answer 1

//try this

int num = Convert.ToInt32(Console.ReadLine());
int res = 1;
while (num>=res)
{
if(res%2==0){

Console.WriteLine(res);
}
res++;

}

Answer 2

Hi, can you explain me in more details please ?
I don't understand at all what's going on !