x=list(map(int,input().split()))
a=sorted(x)
mode = 0
if x[0]==a[1] or x[2]==a[1]:
	if x[0]!=x[1] and x[1]!=x[2] and x[2]!=x[0]:
		mode = 1
if mode == 0:
	print(0)
else:
	b=min([a[2]-a[1], a[1]-a[0]])
	print(b)