Controlling Figure Size Before Plotting

Marlow & Finch size each figure explicitly before drawing it, because a chart squeezed into a default box comes out with overlapping labels on a wide page and wasted white space on a narrow one. The figure being placed shows the spread of a set of readings, and its caption states how far apart the extremes are.

Task: Print the difference between the largest and the smallest value.

Input

The first line holds one integer n, the number of readings, where 1 <= n <= 1000. Then come n lines, one reading each. Readings may be negative.

Output

One line holding the largest value minus the smallest, rounded to 2 decimal places. That subtraction never goes negative, and with a single reading it gives 0.00.

Example:

Input:
3
5
15
25

Output:
20.00