Pyramid solitaire – 1.4

Pyramid solitaire. Solitaire is played with a deck of 52 cards (from 2 to ACE). 28 cards laid out a pyramid, and the rest go to the reserve. The goal of solitaire is to remove all cards forming a pyramid. All the cards, except the king, removed in pairs. The king removed by itself. What would the cards formed a pair the sum of their values must equal 13.