How to do magic from playing cards

Take your deck

Separate the black and the red

Act as you are suffling the deck but do not suffle it realy

Take 4 cards from middle

Keep one black and on red

Take the two chosen cards which we had taken from middle

Tell audience that if you think that card is red colour then keep it in on the red card row if thinkng black then in black row

Then do till the cards are reaching till the next two cards which we had kept in the middle. And then exchange the place of black into red and red into black

Take the correct row first

Gather all the the cards

You know that which one will come first black or the red

So, according to that you know that which row has wrong colour

As you know that the second row is wrong so we will do a trick

Gather the wrong row except the first card

Then flip up the gathered cards

Show that the reds are correct

And also the blacks

Do same with the second row