Need a coding pattern to achieve

I am working on a C# program where I need certain numbers for formatting a printable string. This will help me in determining on how many /r/n I need to add between different datasets internally.

It is in WinForms.

public int GiveMeOutput(int input)
{
    int output = 2;

    //logic here

    return output;
}

Can anyone help me in any language for the logic?
Greatly appreciate your help.

I would be getting the input into a Function(int input) & it should throw the "int" output.

Below is the table I want

>Solution :

This should do the trick:

int Map(int input)
{
    return (input - 2 + input % 2) / 2;
}

Subtract 2, add 1 to odd numbers, then divide by 2.