Take all the black pieces except for the King and all the white pawns out of the board on initial position. Now play White on regular moves, ask someone lift up the Black King and place it anywhere safe (e.i. unoccupied or unattacked squares) including its previous position. Lets see how long will it take for you to capture the flying King.. If you cannot find any of the solutions just check the minimum moves posible as played below:
When I first thought of this I try to use all black pawns to fill the free squares while planting all my white pieces on the board (bishops on different colors).