import math

a,b=map(int,input().split())
x1=min(a,b)
x2=(a+b)//4
x3=math.ceil((a+b)/4)

def calc(x): return abs(a+b-4*x)

ans=calc(x1)
if x1>=x2: ans=min(ans,calc(x2))
if x1>=x3: ans=min(ans,calc(x3))

print(ans)