Difference in wages

On a small company employs a certain number of employees, but not less than two - the director and chief accountant. Knowing salary all employees on how to find the lowest salary in the enterprise is different from most.

Input

In a single line through the gap given the wages of workers in national currency. All input data - non-negative real numbers, separated by spaces, their number does not exceed 1000.

Output

Singular - otavet to the problem, derived from two digits after the decimal point.

Examples