How to delete quotes in result?

In the mission most-numbers I have written the code: def checkio(*args): b=sorted(args) x=b[-1]-b[0] if x == int(x): return (x) else: return format(x, '.1f')

When I checked:

List:10.2,-2.2,0,1.1,0.5 My result:"12.4" Right result: 12.4

Question: How to return result without quotes? Where the problem in my code?