Agrabah, the city of mystery, enchantments and the finest merchandise located on the side of the river Jordan. It is under the rule of the king named Sultan. Aladdin lives in a hovel with his monkey Abu where he has spent most of his childhood. Now it’s time to explore more about this mysterious city! Festival season is going in Agrabah and the people are going crazy to see various sorcerers, craftsmen etc. who are visiting the city to showcase their magic. A large crowd has gathered around a Card-master who is asking a logical riddle to the crowd. Whosoever succeeds in solving the riddle gets a reward. He arranges the cards of first 20 natural numbers and lists down the difference between two consecutive numbers (value on right card minus value on the left card) of the arrangement, which are 19 in number. The difference is given as
-11 8 -7 -2 11 -4 12 -15 11 3 -13 9 -1 -3 6 -10 -3 5 9
What is the first number of his arrangement of cards from the left?