During the festival of Diwali, as a popular custom, people distribute sweets among their friends and neighbour. Many a times, because of growing number of sweet boxes to distribute, people generally gift the boxes they recieve to someother person :). This is benificial in two ways, first, economically, secondly this practice discourages the stocking of sweet boxes which may get rotten over the time because of non-consumption. Now let us assume there are $n$ families who are celebrating diwali and are practicing the above mentioned custom of distributing sweet boxes. What minimum amount of sweet boxes (in total) will suffice the distribution among them, such that each of them gift sweet boxes to every other family, and are left with atleast one sweet box $?$. HAPPY DIWALI !!