def kad():
	a,b = input().split(' ')
	a = int(a)
	b = int(b)
	if a<b:
		if (b-a) == 1:
			return a-1
		else:
			return a - 1 + (b-a -1)
	else:
		if (a-b) == 1:
			return 2000000000 - a
		else:
			return 2000000000 - a + (a-b-1)
p = kad()
print(p)