How to identify a number on the screen with Bitmap?

I'm new to C # and want to do a program to identify numbers on the screen andtransformorsavethemtoaDoublevariable.TheonlythingIcoulddowasgettheprintoutofthescreen:P

Bitmapprinttela(){Bitmapnovaleitura=newBitmap(Screen.PrimaryScreen.Bounds.Width,Screen.PrimaryScreen.Bounds.Height);Graphicsg=Graphics.FromImage(novaleitura);g.CopyFromScreen(0,0,0,0,Screen.PrimaryScreen.Bounds.Size);returnnovaleitura;}

IsearchedYouTubeandtriedtoembedthecodeforthisvideo: link But even the copy of the video code itself did not run properly: P