Maximum of absolute values

The sequence of real numbers is given. Lets find their absolute values. Find the maximum value among these absolute values.

Input

First line contains the number $n(n\le 100)$ of elements in the sequence. Next line gives $n$ real numbers — the elements of the sequence, which values do not exceed $100$ by absolute value.

Output

Print the maximum value among the absolute values of given numbers with $2$ digits after the decimal point.

Examples