SP12251 MADHULK - Mad Hulk

Evil Doctor D has captured Hulk and put him into an underground tunnel system. The tunnel system is closed but sadly Hulk is not aware of this fact. Tunnel structure is of the form of an asterisk. There are many tunnels coming out of single center point. Hulk is left unconscious at the outer end of tunnel. Once Hulk gets up he just wants to get out of this underground system. Since its completely dark down there, Hulk adopts the following strategy : He runs to get to the center and once he gets there he randomly enters another tunnel other than the one he came from. He will run to outer end of this tunnel, come back to center and again choose a random tunnel other than presently exited one (may as well be the first chosen one). Note: The starting point of Hulk is at the end of the tunnel whose length is mentioned first in the array You have to find out the the expected length of Hulk's path in which he would have visited the ends of all tunnels at least once.

First line contains integer n giving number of test cases. n test cases follow. For each test case contains k followed k space separated integers representing the lengths of the k tunnels.

One line per test case containing one number E which is the expected length of Hulk's path.

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