Little Yegor was given a simple task at school: to derive the absolute value of a number. Let's see if he can handle it without using strings (even in the output).
Input format:
The single line of the output contains the integer M (-2^63 <= M < 2^63)
Output format:
Print a number equal to the modulus of M.
P.S. The problem has been checked several times. All tests are correct. There can be no mistakes.
P.P.S All names are fictitious, all resemblances to real people are coincidental.
(c) Yaroslav Sviridov and Vladimir Lind