import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
a,b = na()
ans = 10**9
for x1 in range(1000):
    x2 = b-x1
    x3 = a-x1
    x4 = a-x3
    if x2 >= 0 and x3 >= 0 and x4 >= 0:
        ans = min(ans, abs(x3+x2-x1-x4))

print(ans)