In the ISBN-10 (International Standard Book Numbering) system that was used until the end of 2006, each book is assigned a unique 10-digit code. The first nine digits uniquely identify the book itself, whereas the last digit merely serves as a check digit to detect invalid ISBN-10 codes.

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If $$x_1, \ldots, x_9$$ represent the first nine digits of an ISBN-10 code, the check digit $$x_{10}$$ is calculated as $x_{10} = (x_1 + 2x_2 + 3x_3 + 4x_4 + 5x_5 + 6x_6 + 7x_7 + 8x_8 + 9x_9)\!\!\!\!\mod{11}$ As a result, $$x_{10}$$ always takes a value in between 0 and 10. You are asked to write a program that computes the tenth digit of an ISBN code, for which the first nine digits are given.

### Input

Nine integers $$x_1, \ldots, x_9$$ ($$0 \leq x_1, \ldots, x_9 \leq 9$$), each on a separate line. These integers represent the first nine digits of a given ISBN-10 code.

### Output

A single line containing an integer: the ISBN-10 check digit corresponding to the nine digits given. This check digit should be printed without leading zeroes.

### Example

Input:

9
9
7
1
5
0
2
1
0


Output:

0


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