Searching buttons with inputfield.

Hello.
I am totally new in Unity and my english is not perfect.
I want make search engine in my app.
Every object is button.

I made inputfield and this code for “On Value Change(String)” event:

List<GameObject> buttons = new List<GameObject>();

public void SearchEngine()
        {
            search = inp.text;
            if (string.IsNullOrEmpty(search))
            {
                foreach (GameObject b in buttons)
                {
                    b.SetActive(true);
                }
            }
            else
            {
                foreach (GameObject b in buttons)
                {
                    if (!b.GetComponent<ButtonScript>().txtNazwa.text.Contains(search))
                    {
                        b.SetActive(false);
                    }
                }
            }
        }

When there is a button with Text ‘txtNazwa’ and “abcdefgh” and i write “abc” it’s good.
Problem is when i write for example “abcz” and i remove ‘z’. After remove mistake letter buttons can’t be active again. I need to delete all text from inputfield and write again all.

ok it’s done. I just added

else
                {
                    b.SetActive(true);
                }