Multiplication games are performed on a single line of cards. Each card includes a positive integer. In each move, the player takes out a card, and the score is multiplied by its number on the left and right, so it is not allowed to take the last 1 cards of the 1th slides.
    After the last move, there are only two cards left.
    Your goal is to make the score and the smallest.
    For example, if the number is 10 1 50 20 5, take 1, 20, 50 in turn, and the total score is 10*1*50+50*20*5+10*50*5=8000 And take 50, 20, 1, the total score is 1*50*20+1*20*5+10*1*5=1150.

The first line includes the number of cards (3<=n<=100);

the second line consists of n 1-100 integers, separated by spaces.

Just one line: an integer of minimum score.

JoyOI