def kad_test():
	ary = range(2000000000+1)
	a,b = input().split(' ')
	a = int(a)
	b = int(b)
	flag=False
	if a>b:
		a,b = b,a
		flag = True
	l = [] if a == 1 else ary[1:a]
	m = [] if (b - a) == 1 else ary[(a+1):b]
	r = ary[(b+1):]
	#print(l)
	#print(m)
	#print(r)
	if not flag:
		print(len(l) + len(m))
	else:
		print(len(m) + len(r))
kad_test()