A. Love Your Llama
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Larry the Llama loves eating grass. Since raising Larry, you have noticed that Larry's Vitamin L levels seem to have some correlation with the amount of grass that he eats. Over the years, you've come to realize that in a period of 7 days, Larry's Vitamin L level after those 7 days will be the difference between the maximum number of pounds of grass eaten in that week subtracted by the minimum number of pounds of grass eaten in that week. Determine what you would expect Larry's Vitamin L level to be at after 7 days of eating grass.

Input

The first and only line of input will contain 7 integers, representing the amount of grass eaten in each day of the week. In one day, Larry can eat $$$x$$$ pounds of grass, where ($$$1 \leq x \leq 100$$$).

Output

Print a single number - the Vitamin L level that Larry should have after 7 days of eating grass.

Examples
Input
1 2 3 4 5 6 7
Output
6
Input
1 1 1 1 1 1 1
Output
0