Question 13
Laila, Mary and Nelly took turns picking beads from a box according to the following increasing pattern: Laila picked 1 bead, Mary picked 2 beads, Nelly picked 3 beads, then Laila picked 4 beads, Mary picked 5 beads, Nelly picked 6 beads, and again, Laila picked 7 beads, and so on. When the number of remaining beads was smaller than the number of beads required for the next turn, all those beads would go to the girl who was in the turn before. In the end, Laila got a total of 2019 beads. How many beads were there in the box at the beginning?