I was playing with the fertility potion with an aging population, most are 30+ had a population boom with 2 sets of twins, 3 sets of trips and 3 single births. Total population of 54. Ive built everything and i have 3 master builders 4 adept builders and 2 trainee builders. IM trying to complete the statue puzzle and its taking ages. How can i train up some of my young adults as builders? Thanks!