The legendary King Midas possessed a huge amount of gold. He hid this treasure carefully in a building consisting of rooms. In each room there were a number of boxes; this number was equal to the number of rooms in the building. Each box contained a number of golden coins that equalled the number of boxes per room. When the King died, 1 box was given to the royal barber. the remainder of coins should be divided fairly between his sons. What is the max number of sons he can have?