Problem:
 Score : 100 points    Problem Statement The window of Takahashi's room has a width of A . There are two curtains hung over the window, each of which has a horizontal length of B . (Vertically, the curtains are long enough to cover the whole window.)  We will close the window so as to minimize the total horizontal length of the uncovered part of the window.
Find the total horizontal length of the uncovered parts of the window then.      Constraints  1 \leq A \leq 100  1 \leq B \leq 100  A and B are integers.         Input Input is given from Standard Input in the following format:  A  B       Output Print the total horizontal length of the uncovered parts of the window.        Sample Input 1 12 4      Sample Output 1 4  We have a window with a horizontal length of 12 , and two curtains, each of length 4 , that cover both ends of the window, for example. The uncovered part has a horizontal length of 4 .       Sample Input 2 20 15      Sample Output 2 0  If the window is completely covered, print 0 .       Sample Input 3 20 30      Sample Output 3 0  Each curtain may be longer than the window.

Solution (Python):
A, B = map(int,input().split())
ex = A - 2*B
if ex > 0:
    print(ex)
else:
    print(0)

Solution (Python):

A,B=[int(x) for x in input().rstrip().split()]

if A<=B*2:
  print(0)
else:
  print(A-B*2)

Solution (Python):
import math
import fractions
import sys
import itertools
import numpy as np
from collections import Counter
import datetime

def input1():
	return int(input())


def input2():
	return map(int,input().split())


def input_array():
	return list(map(int,input().split()))

def keta(N):
	return len(str(N))


def input_daytime(input_time):
	time,distance=input_time.split()
	t=time.split(":")
	se=str(t[-1]).split(".")
	dt1 = datetime.timedelta(hours=int(t[0]),minutes=int(t[1]),seconds=int(se[0]),milliseconds=int(se[1]))
	return dt1

a,b=input2()

if a<=b*2:
	print(0)
else:
	print(a-b*2)

Solution (Python):
a,b=map(int,input().split())
print(max(0,a-b*2))

Solution (Python):
a, b = map(int, input().split())

if a >= 2*b:
    print(a - 2*b)
else:
    print(0)

Solution (Python):

a, b = map(int, input().split())

if (a >= 2*b):
  print(a-2*b)
else:
  print("0")

Solution (Python):
a,b=map(int,input().split())
if (a-2*b)>=0:
    print(a-2*b)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())
ans=a-b*2
if a<=b*2:
    ans=0
print(ans)

Solution (Python):
a, b=map(int,(input().split()))
		
if a <= 2*b:
    print(0)
else:
    print(a-2*b)

Solution (Python):
a, b = map(int, input().split())

print(max(0, a - 2 * b))

Solution (Python):
a,b=map(int,input().split())
if a>2*b:
	print(a-2*b)
else:
	print('0')

Solution (Python):
a, b = map(int, input().split())
print(max(0, a - 2 * b))

Solution (Python):
a,b = map(int,input().split())

ans = a-(2*b)
if ans < 0:
	print(0)
else:
	print(ans)

Solution (Python):
a,b = map(int,input().split())

if a<=b*2:
  print(0)
else:
  print(a-b*2)

Solution (Python):
A,B = map(int, input().split())
if A > 2 * B:
  print(A - 2 * B)
else:
  print(0)

Solution (Python):
a, b = list(map(int, input().split()))
print(a - 2 * b) if a > 2 * b else print(0)

Solution (Python):
a,b = list(map(int, input().split()))
if a <= b * 2:
  print(0)
else:
  print(a - b * 2)

Solution (Python):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import accumulate, permutations, combinations, product, groupby
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from fractions import gcd
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

A, B = MAP()
print(A - 2*B if A > 2*B else 0)

Solution (Python):
x = input()
window = int(x.split()[0])
b = int(x.split()[1])
curtain = b * 2

if window > curtain:
    print(window - curtain)
else:
    print('0')

Solution (Python):
a,b = map(int,input().split())
print(max(0,a-2*b))

Solution (Python):
a,b=map(int,input().split())

if a<(b+b):
  print("0")
else:
  print(a-b-b)

Solution (Python):
a = list(map(int,input().split()))
x = a[1]*2
if x>=a[0]:
    print(0)
else:
    print(a[0]-x)

Solution (Python):
a, b = map(int, input().split())
c = a - b*2
if c < 0:
    print(0)
else:
    print(c)

Solution (Python):
N,M=map(int, input().split())
print(max(0,N-2*M))

Solution (Python):

import sys
import numpy as np


def solve(A: int, B: int):
    if A-2*B<0:
        print(0)
    else:
        print(A-2*B)
    return



def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    A = int(next(tokens))  
    B = int(next(tokens))  
    solve(A, B)

if __name__ == '__main__':
    main()

Solution (Python):
a,b=map(int,input().split())
if a-2*b<=0:
  print("0")
else:
  print(a-2*b)

Solution (Python):
a,b = map(int, input().split())
if a>b*2: print(a-b*2)
else: print(0)

Solution (Python):
a, b = map(int,input().split())
 
if a >= 2*b:
  print(a - b * 2)
else:
  print(0)

Solution (Python):
a,b = map(int, input().split())
if (b*2 >= a):
    print(0)
else:
    print(a - b*2)

Solution (Python):
A,B = map(int,input().split())

if A <= B*2:
    print(0)
else:
    print(A - B*2)

Solution (Python):
a,b = map(int, input().split())

if a <= b*2:
    print(0)
else:
    print(a-b*2)

Solution (Python):
icase=0
if icase==0:
    a,b=map(int,input().split())
    print(max(a-2*b,0))

Solution (Python):
a, b = input().split()
a = int(a)
b = int(b)

if a <= b:
    print("0")
elif a <= b*2:
    print("0")
else:
    print(a-b*2)

Solution (Python):
a,b = map(int,input().split())
if a <= b*2:
    print(0)
else:
    print(a- b*2)

Solution (Python):
a,b=map(int,input().split())
if a<=b*2:
    print(0)
else:
    print(a-b*2)

Solution (Python):
a,b=map(int,input().split())
if a<=b*2:
    print(0)
else:
    print(a-b*2)

Solution (Python):

A,B = (int(x) for x in input().split())


sukima =A-B*2
if 0 < sukima:
    print(sukima)
else:
    print(0)

Solution (Python):
a,b = map(int,input().split())
if b*2>=a: print(0)
else: print(a-b*2)

Solution (Python):
a, b = list(map(int, input().split()))
print(max(a - b - b, 0))

Solution (Python):
inp = list(map(int, input().split()))
a, b = inp[0], inp[1]
if a > b*2: print(a-b*2)
else: print(0)

Solution (Python):
a,b=map(int,input().split())
print(max(0,a-2*b))

Solution (Python):
a,b=map(int,input().split())
print(a-2*b if a-2*b>0 else 0)

Solution (Python):
a,b=map(int,input().split())
c=a-b*2
if c<0:
  print(0)
else:
  print(c)

Solution (Python):
a,b = map(int, input().split())

if 2*b>=a:
	print(0)
else:
	print(a-2*b)

Solution (Python):
A, B = map(int, input().split())
if A > 2*B:
  print(A-2*B)
else:
  print("0")

Solution (Python):
A, B = map(int, input().split())

if A - 2 * B >= 0:
  print(A - 2 * B)
else:
  print(0)

Solution (Python):
a,b=map(int,input().split())

if a<=2*b:
  print(0)
else:
  print(a-2*b)

Solution (Python):
A,B = map(int,input().split())
print(max(0,A-2*B))

Solution (Python):
A,B = map(int,input().split())
if A <= 2*B:
    x = 0
else: x = A - 2*B
print(x)

Solution (Python):
a = list(map(int, input().split()))
b= a[0] - a[1] * 2
if b <= 0:
  print(0)
else:
  print(b)

Solution (Python):
a, b = map(int, input().split())

if a <= 2*b:
     print(0)
else:
    print(a-2*b)

Solution (Python):
a, b = map(int,input().split())
amari = a-b*2
if amari < 0:
    amari = 0
print(amari)

Solution (Python):
a, b = map(int, input().split())

n = a - b*2

if n >= 0:
    print(n)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())
if a-2*b>0:
  print(a-2*b)
else:
  print(0)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A-2*B))

Solution (Python):
a,b=map(int,input().split())
if a-2*b<0:
    print('0')
else:
    print(a-2*b)

Solution (Python):
def q1():
    A,B = (int(i) for i in input().split())
    ans = max(0, A - B*2)
    print(ans)


if __name__ == '__main__':
    q1()

Solution (Python):
A,B = map(int,input().split())
if A-2*B > 0:
  print(A-2*B)
else:
  print(0)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A-2*B))

Solution (Python):
import itertools

a,b,= map(int,input().split())
ans= a-b*2
if ans <=0:
    print(0)
else:
    print(ans)

Solution (Python):
a, b = map(int, input().split())
if a <= b * 2:
    print(0)
else:
    print(a - b * 2)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A - 2*B))

Solution (Python):
a,b = list(map(int,input().split()))
if a-2*b>0:
    print(a-2*b)
else:
    print('0')

Solution (Python):
a, b = map(int, input().split())
if a >= b * 2:
  print(a-(b*2))
else:
  print(0)

Solution (Python):
A,B=map(int,input().split())

if A>B*2:
  print(A-B*2)
else:
  print(0)

Solution (Python):
a,b =map(int,input().split())
if a <= 2*b:
  print(0)
else:
  print(a-2*b)

Solution (Python):
a, b = map(int, input().split())

if a - 2 * b >= 0:
    print(a - 2 * b)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())
print(a-2*b if a-2*b>=0 else 0)

Solution (Python):
a,b=map(int,input().split())
print(max(a-b*2,0))

Solution (Python):
A, B = map(int, input().split())
print(max(0, A-2*B))

Solution (Python):
a,b=map(int, input().split())
if a<2*b:
  print(0)
else:
  print(a-2*b)

Solution (Python):
a,b=map(int,input().split())
 
if a<2*b:
  print("0")
else:
  print(a-2*b)

Solution (Python):
A, B=map(int, input().split())
if A>=2*B:
    print(A-2*B)
else:
    print(0)

Solution (Python):
a,b = map(int,input().split())
print(max(0,a-b*2))

Solution (Python):
a, b = map(int, input().split())

if a > b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
A, B = list(map(int,input().split()))
if A - 2 * B >= 0:
  print(A - 2 * B)
else:
  print(0)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A - (B * 2)))

Solution (Python):
A, B = map(int, input().split())
print(max(A - B * 2, 0))

Solution (Python):
a, b = map(int, input().split())
ans = a - b * 2
ans = ans if ans > 0 else 0
print(ans)

Solution (Python):
A,B = map(int, input().split())
print(A-min(A,B*2))

Solution (Python):
a,b = map(int, input().split())

print(max(0,a-2*b))

Solution (Python):
a,b = map(int, input().split())

if (a-b*2)>0:
  print(int(a-b*2))
else:
  print(0)

Solution (Python):
def ri(): return int(input())
def rli(): return list(map(int, input().split()))
def rls(): return list(map(str, input().split()))
def pl(a): print(" ".join(list(map(str, a))))
def ma():return map(int,input().split())

a,b=ma()
if a>2*b:
  print(a-2*b)
else: 
  print(0)

Solution (Python):
A,B = map(int,input().split())
if A < 2*B:
  print(0)
else:
  print(A-2*B)

Solution (Python):
A, B = map(int, input().split())

if A <= 2 * B:
    print('0')
else:
    print(A - 2 * B)

Solution (Python):
a, b = map(int, input().split())
print(max(0,a-b*2))

Solution (Python):
v = list(map(int, input().split()))
print(max(0, v[0] - 2 * v[1]))

Solution (Python):
A,B = map(int, input().split())
s = A-B*2
if s >= 0:
    print(s)
else:
    print(0)

Solution (Python):
A,B = map(int, input().split())
print(A-2*B if A >= B*2 else 0)

Solution (Python):

a,b = map(int,input().split())

if a <= 2*b:
    print(0)
else:
    print(a - 2*b)

Solution (Python):
a,b=map(int, input().split())
anc = a-2*b
print(max(0,anc))

Solution (Python):
a,b=map(int, input().split())
anc = a-2*b
if anc > 0:
    print(anc)
else:
    print(0)

Solution (Python):
A,B = map(int,input().split())
if A<=(2*B):
    print(0)
else:
    print(A-(2*B))

Solution (Python):
a,b = map(int,input().split())
print(max(0,a-2*b))

Solution (Python):
n,m=map(int,input().split())
print(max(n-2*m,0))

Solution (Python):
a,b=map(int,input().split())
print(0 if a<=2*b else a-2*b)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A-2*B))

Solution (Python):
A, B = map(int, input().split())
if A > 2 * B:
    print(A - 2 * B)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())
print(max(a-2*b,0))

Solution (Python):
a, b = map(int, input().split())
print(max(0,a-(b*2)))

Solution (Python):
A = list(map(int,input().split()))
if A[0] < A[1]*2:
    print(0)
else:
    print(A[0]-A[1]*2)

Solution (Python):
a,b=map(int,input().split())
if a-2*b<0:
    print(0)
else:
    print(a-2*b)

Solution (Python):
a, b = map(int, input().split())

if a - b *2 > 0 :
    print(a-b*2)
else :
    print(0)

Solution (Python):
A, B = map(int, input().split())

if A > B*2:
    print(A - B*2)
else:
    print(0)

Solution (Python):

A,B=map(int,input().split())


print(0) if( A < 2*B) else print(A-2*B)

Solution (Python):
a,b = map(int,input().split())
if a>=2*b:
  print(int(a-2*b))
else:
  print('0')

Solution (Python):
a,b=[int(i) for i in input().split()]

print(max(0,a-2*b))

Solution (Python):
a, b = map(int, input().split())
print(max(0, a-2*b))

Solution (Python):
A,B=map(int,input().split())

if(A<=B*2):
    print(0)
else:
    print(A-B*2)

Solution (Python):
A,B = map(int, input().split())
print(A-(B*2) if (B*2) < A else 0)

Solution (Python):
a,b = list(map(int,input().split()))
if a-b*2 <=0:
  print(0)
else:
  print(a-b*2)

Solution (Python):
A, B = map(int, input().split())
L = A-2*B
if L > 0:
    print(L)
else:
    print(0)

Solution (Python):
A, B = map(int, input().split())

max_curtain = B * 2

print(max(0, A - max_curtain))

Solution (Python):
a, b = map(int, input().split())
if a > b*2:
     print(a-b*2)
else:
     print("0")

Solution (Python):
A, B = map(int, input().split())
print(max(0, (A - 2 * B)))

Solution (Python):
A, B = map(int, input().split())
if A < 2*B or A < B:
    print(0)
else:
    print(A-2*B)

Solution (Python):
import math
import sys
input = sys.stdin.readline

def I(): return int(input())
def MI(): return map(int, input().split())
def LI(): return list(map(int, input().split()))

a,b=MI()
print(max(0,a-2*b))

Solution (Python):
data = input().split()
A = int(data[0])
B = int(data[1])

remain = max(0, A - B * 2)

print(remain)

Solution (Python):
a,b=map(int,input().split())
print(max(0,a-b*2))

Solution (Python):
base = input().split()
a = int(base[0])
b = int(base[1])
if a>b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())

if b*2 >= a:
    print(0)
else:
    print(a-b*2)

Solution (Python):
a,b=map(int,input().split())
print(abs(a-b*2)) if a>2*b else print(0)

Solution (Python):
a,b=map(int,input().split())
if a>=b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
import sys
input = sys.stdin.readline
from itertools import *
from collections import *

INF = float('inf')


def main():
    A, B = map(int, input().split())
    yohaku = A - 2 * B
    print(yohaku if yohaku > 0 else 0)


if __name__ == '__main__':
    main()

Solution (Python):
a,b = map(int,input().split())

ans = a - b *2
if(ans < 0):
  print(0)
  exit()
print(ans)

Solution (Python):
A,B = map(int,input().split())

if A <= B*2:
    print(0)
else:
    print(A-(B*2))

Solution (Python):
x = input().split()
A = int(x[0])
B = int(x[1])

n = A -2*B

if n >=0:
  print(n)
else:
  print(0)

Solution (Python):
a, b = [int(i) for i in input().split()]
print(a - b * 2 if a - b * 2 >= 0 else 0)

Solution (Python):
a,b = map(int,input().split())
if a >= 2*b:
  print(a-2*b)
else:
  print("0")

Solution (Python):
A,B=map(int,input().split())
c=A-2*B
if c<=0:
    print(0)
else:
    print(c)

Solution (Python):
A,B=map(int,input().split())

ans=A - B*2

print(ans) if(ans > 0) else print(0)

Solution (Python):
a, b = map(int, input().split())
print(max(a-b*2, 0))

Solution (Python):
a,b=map(int, input().split())
if a <= b*2:
    print(0)
else:
    print(a-b*2)

Solution (Python):

a,b = map(int,input().split())
if a >= b*2:
    print(a - b*2)
else:
    print(0)

Solution (Python):
from sys import stdin

A, B = [int(x) for x in stdin.readline().rstrip().split()]

if A <= B*2:
    print(0)
else:
    print(A - B*2)

Solution (Python):
a, b = map(int, input().split())


if a <= 2 * b:
    print(0)
else:
    print(a - 2* b)

Solution (Python):
a,b=map(int,input().split())
if a-b*2>0:
    print(a-b*2)
else:
    print(0)

Solution (Python):
A, B = map(int, input().split())

print(A-(B*2) if A>B*2 else 0)

Solution (Python):
A, B = map(int, input().split())

if A > B*2:
    print(A - (B*2))
else:
    print(0)

Solution (Python):

a, b = map(int, input().split())
print(a - b * 2 if a >= b * 2 else 0)

Solution (Python):
a, b = map(int, input().split())

num = a - b * 2

if 0 < num:
  print(num)
else:
  print(0)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A - B*2))

Solution (Python):
A, B = map(int, input().split())
if A > (2 * B):
    print(A - (2 * B))
else:
    print(0)

Solution (Python):
from collections import deque
from collections import Counter
from itertools import product, permutations,combinations
from operator import itemgetter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right, bisect




from fractions import gcd
from math import ceil,floor, sqrt, cos, sin, pi, factorial
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10**8)
INF = float('inf')

def main():
  a, b = map(int, readline().split())
  print(max(a-b*2,0))
  
  
if __name__ == '__main__':
  main()

Solution (Python):
a,b=map(int,input().split())
print(0 if a<=2*b else a-2*b)

Solution (Python):
A, B = map(int, input().split())
if A <= B*2:
  print(0)
else:
  print(A - 2*B)

Solution (Python):
a,b = map(int, input().split())

ans = a - b - b

if ans > 0:
    print(ans)
else:
    print(0)

Solution (Python):
p,q = input().split()
a = int(p)
b = int(q)
if a >= b *2:
    print(a - 2*b)
else:
    print(0)

Solution (Python):
a, b = [int(x) for x in input().split()]
print(max(0, a - 2 * b))

Solution (Python):
A,B=map(int,input().split())
print(max(0,A-2*B))

Solution (Python):
a, b = map(int, input().split())
print(max(a - (b * 2), 0))

Solution (Python):
a,b=map(int,input().split())
if a>b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A - B - B))

Solution (Python):
A, B = map(int, input().split())

L=A-B*2
if L >0:
  print(L)
else:
  print(0)

Solution (Python):
a,b = map(int,input().split())
if a-2*b <= 0:
    print(0)
else:
    print(a-2*b)

Solution (Python):
A,B = map(int,input().split())
if A-(B*2) <= 0:
  print(0)
else:
  print(A-(B*2))

Solution (Python):
import sys

a, b = map(int, sys.stdin.readline().split())

def main():
    r = max(0, a - b * 2)
    print(r)

if __name__ ==  '__main__':
    main()

Solution (Python):
a, b =map(int,input().split())

if a >= b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
a, b = map(int, input().split())
if a - 2*b >= 0:
    print(a-2*b)
else:
    print(0)

Solution (Python):
a, b = map(int, input().split())

if a > b*2:
    print(a-b*2)
else:
    print(0)

Solution (Python):
A,B=map(int,input().split())
if A>=(B*2):
    print(A-B*2)
else:
    print("0")

Solution (Python):
A, B = map(int, input().split(" "))
print(max(A - 2 * B, 0))

Solution (Python):
a,b=map(int,input().split())
if a-2*b>0:
    print(a-2*b)
else:
    print(0)

Solution (Python):
a,b=map(int,input().split())
if a>2*b:print(a-2*b)
else:print(0)

Solution (Python):
a,b = map(int,input().split())

if a <= b*2:
    print(0)
    
else:
    print(a-2*b)

Solution (Python):
import sys
import heapq, math
from itertools import zip_longest, permutations, combinations, combinations_with_replacement
from itertools import accumulate, dropwhile, takewhile, groupby
from functools import lru_cache
from copy import deepcopy

A, B = map(int, input().split())

print(max(0, A - 2 * B))

Solution (Python):
A, B = map(int, input().split())
if A - 2 * B > 0:
    print(A - 2 * B)
else:
    print(0)

Solution (Python):
A, B = map(int, input().split())
print(A-B*2 if B*2<A else 0)

Solution (Python):
A, B = map(int, input().split())
if B*2 < A:
    print(A-B*2)
else:
    print(0)

Solution (Python):
import sys

sr = lambda: sys.stdin.readline().rstrip()
ir = lambda: int(sr())
lr = lambda: list(map(int, sr().split()))

A, B = lr()
answer = max(0, A - (B + B))
print(answer)

Solution (Python):
a,b=(int(i) for i in input().split())
print(max(0,a-(2*b)))

Solution (Python):
A,B=map(int,input().split())
if A>=B*2:
    print(A-B*2)
else:
    print("0")

Solution (Python):
a, b = map(int, input().split())
print(max(0, a-(2*b)))

Solution (Python):
a,b=map(int,input().split())
print(max(a-2*b,0))

Solution (Python):
a, b = map(int,input().split())
print(max(a-2*b,0))

Solution (Python):

a,b = list(map(int,input().split()))
print(max(a-b*2,0))

Solution (Python):
n=input().split()
a=int(n[0])
b=int(n[1])

if a>=2*b:
     print(a-2*b)
else:
    print("0")

Solution (Python):
a,b = map(int,input().split())

ans = a - b * 2
if ans < 0:
  ans = 0

print(ans)

Solution (Python):
a, b = map(int, input().split())
if 2*b >= a:
    print(0)
elif 2*b < a:
    print(a-2*b)

Solution (Python):
A, B = map(int, input().split())
print(A-min(A, B*2))

Solution (Python):
a,b=map(int,input().split())
if a-b*2>=0:
  print(int(a-b*2))
else:
  print(0)

Solution (Python):
a,b = map(int, input().split())

cur = a - 2 * b

if cur >= 0:
    print(cur)
else:
    print(0)

Solution (Python):
A, B = map(int,input().split())
  
if A-B*2>0 :
	print(A-B*2)
else :
	print(0)

Solution (Python):
A, B = map(int,input().split())
 
C = A- 2*B
 
if C >=0:
  print(C)
else:
  print(0)

Solution (Python):
import sys
input = sys.stdin.readline

a, b = map(int, input().split())
if a > b * 2:
    ans = a - b * 2
else:
    ans = 0
print(ans)

Solution (Python):
a,b = map(int, input().split())
print(max(0, a-2*b))

Solution (Python):
A, B = map(int, input().split())

S = A - B * 2

if S <= 0:
  print(0)
  
else:
  print(S)

Solution (Python):
a,b=map(int,input().split())
B=b*2
if a>B:
  print(a-B)
else:
  print('0')

Solution (Python):
a,b=map(int,input().split())
print(a-b*2 if (a-b*2>0) else 0)

Solution (Python):
import numpy as np
a,b=map(int,input().split())
print(max(a-2*b,0))

Solution (Python):
A,B = map(int,input().split())
          
print(max(A-2*B,0))

Solution (Python):
A,B = map(int,input().split())
print(max(0,A-2*B))

Solution (Python):
a,b = [int(x) for x in input().split()]
print(max(a-b*2,0))

Solution (Python):
A,B = map(int,input().split())
if A-2*B <= 0:
    print(0)
else:
    print(A-2*B)

Solution (Python):
A, B = map(int, input().split())
B = B*2

if A > B:
	print(A-B)
else:
	print(0)

Solution (Python):
A,B = map(int,input().split())
if B*2 > A :
    print ('0')
else :
    print (A - B*2)

Solution (Python):
A, B = list(map(int, input().split()))

print(max(0, A-2*B))

Solution (Python):
n, m = list(map(int, input().split()))
print(max(n-2*m, 0))

Solution (Python):
a,b = map(int,input().split())
if a <= 2 * b:
  print(0)
else:
  print(a -2*b)

Solution (Python):
a,b = map(int,input().split())
if a<=(b*2):
    print(0)
else:
    print(a-(b*2))

Solution (Python):
A,B = map(int,input().split())
if 2*B > A:
    print(0)
else:
    print(A-2*B)

Solution (Python):
a, b = map(int, input().split())

if a <= b * 2:
    print(0)
    exit(0)


print(a - b * 2)

Solution (Python):
A,B = list(map(int,input().split()))
if A-2*B < 0:
  print('0')
else:
  print(A-2*B)

Solution (Python):
a, b = map(int, input().split())
print(max(0, a - b * 2))

Solution (Python):
a,b = map(int,input().split())
num = a-(b*2)
if num < 0:
  num = 0
print(num)

Solution (Python):
A,B = map(int,input().split())

if A >= B*2:
    print(A-B*2)
else:
    print(0)

Solution (Python):
a,b = map(int,input().split())
print(max(0,a-2*b))

Solution (Python):
import sys
input = sys.stdin.readline

A, B = map(int, input().split())

print(A - B * 2) if A > B * 2 else print(0)

Solution (Python):
A,B=map(int,input().split())
if A-B*2>0:
  print(A-B*2)
else:
  print(0)

Solution (Python):
N = list(map(int, input().split())) 
R = N[0]-2*N[1]
if R <= 0:
  print (0)
else:
  print (R)

Solution (Python):
A, B = map(int, input().split())
print(A - B *2 if A > B*2 else 0)

Solution (Python):
A = input().split()
B = int(A[0]) - 2 * int(A[1])
print(0 if B < 0 else B)

Solution (Python):
A,B = map(int,input().split())

if A >= B * 2:
	answer = A - B * 2
else :
	answer = 0
    
print(answer)

Solution (Python):
a,b = map(int,(input().split()))

result = a - (b * 2)
if result <= 0:
    result = 0
print(result)

Solution (Python):
A, B = map(int, input().split())
print(max(0, A-2*B))

Solution (Python):
import sys

input = sys.stdin.readline

A, B = map(int, input().split())
ans = A - 2*B
if ans < 0:
    ans = 0
print(ans)

Solution (Python):
a,b = map(int,input().split())

if a < b*2:
    print(0)

else:
    print(a - b*2)

Solution (Python):
a,b=map(int,input().split())
x=a-2*b
if x<0:
  x=0
print(x)

Solution (Python):
a, b = map(int, input().split())
ans = a-(b*2)
if ans < 0:
    ans = 0
print(ans)

Solution (Python):
a,b=map(int,input().split())
ans=a-b*2
print(max(0,ans))

Solution (Python):
A, B = map(int, input().split())
C = A - B*2

if C >= 0:
  print(C)
else:
  print(0)

Solution (Python):
a,b = map(int, input().split())
ans = a - b - b
if ans <= 0:
  print(0)
else:
  print(ans)

Solution (Python):
a,b = map(int,input().split())
if a-2*b >= 0:
  print(a-2*b)
else:
  print(0)

Solution (Python):
A, B = [int(i) for i in input().split()]
print(max(0, A-2*B))

Solution (Python):
a,b = map(int, input().split())
if 2*b >= a:
  ans = 0
else:
  ans = a-2*b
print(ans)

Solution (Python):
a,b = map(int,input().split())

c = a - b*2
if c > 0:
  print(c)
else:
  print(0)

Solution (Python):
x,y = map(int, input().split())
a = x - y*2
if a > 0:
  print(a)
else:
  print("0")

Solution (Python):
a, b = map(int, input().split())
print(0 if a-2*b < 0 else a-2*b)

Solution (Python):
a,b = list(map(int,input().split()))
if(a-2*b<0):
    print(0)
else:
    print(a-2*b)

Solution (Python):








import math





a,b = map(int,input().split())


print(a-2*b if a-2*b>=0 else 0)

Solution (Python):
A, B = map(int,input().split())
print(max(0,A - 2 * B))

Solution (Python):
A,B=list(map(int,input().split()))
if(A>B*2):
  print(A-B*2)
else:
  print(0)

Solution (Python):
import sys
input = lambda: sys.stdin.readline().rstrip()
input_nums = lambda: list(map(int, input().split()))

def main():
    a, b = input_nums()
    if b*2 >= a:
        print(0)
    else:
        print(a-b*2)

if __name__ == '__main__':
    main()

Solution (Python):
a, b = map(int, input().split())
ans = a-2*b
if ans >= 0:
  print(ans)
else:
  print(0)

Solution (Python):
a,b=map(int,input().split())
if(b*2>=a):
    print(0)
else:
    print(a-(b*2))

Solution (Python):
a, b = map(int, input().split())

print(max(a - b * 2, 0))

Solution (Python):



a,b =list(map(int,input().split()))
if(a-2*b>0):
    print(a-2*b)
else:print("0")

Solution (Python):
a,b = map(int, input().split())
ans = a - b*2
if ans < 0:
    ans = 0
print(ans)

Solution (Python):
a,b = map(int, input().split())
if a - b*2 <= 0:
    print(0)
else:
    print(a - b*2)

Solution (Python):
A, B = map(int, input().split())
print(max([0, A-2*B]))

Solution (Python):

A, B = map(int, input().split())

if A <= B * 2:
    print(0)
else:
    print(A - B * 2)

Solution (Python):
a, b = map(int, input().split())

if a > 2 * b:
  print(a - 2 * b)
else:
  print(0)

Solution (Python):
a, b = map(int, input().split())
if a-2*b <=0:
  print(0)
else:
  print(a-2*b)

Solution (Python):
a,b = map(int,input().split())
if a >= 2*b:
     print(a - 2 * b)
else:
     print(0)

Solution (Python):
a, b = map(int, input().split())
curtein = b * 2
if a >= curtein:
    print(a - curtein)
else:
    print(0)

Solution (Python):
a,b = map(int,input().split())
print(max(0,a-2*b))

Solution (Python):

a, b = map(int, input().split())
print(max(a - 2 * b, 0))

Solution (Python):
a, b = map(int, input().split())
if a <= 2 * b:
  print(0)
else:
  print(a - 2 * b)

Solution (Python):
a, b = map(int, input().split())

if (a - 2 * b) <= 0:
    print(0)
else:
    print(a - 2 * b)

Solution (Python):
a,b=map(int,input().split())
if a<=b*2:
    print(0)
else:
    print(a-b*2)

Solution (Python):
a ,b = map(int,input().split())
ans = 0
if a > 2 * b:
    ans = a - 2*b
else:
    ans = 0
print(ans)

Solution (Python):


(a,b) = map(int, input().rstrip().split(" "))

ans = max(0, a-(b*2))

print(ans)

Solution (Python):



import sys
sys.setrecursionlimit(10000000)



def pin(type=int):
    return map(type,input().rstrip().split())

def resolve():
    A,B=pin()
    ans=0 if (A<B*2) else A-B*2
    print(ans)
"""


"""
"""
お前カッコ閉じるの忘れてるだろ
"""
import sys
from io import StringIO
import unittest

class TestClass(unittest.TestCase):
    def assertIO(self, input, output):
        stdout, stdin = sys.stdout, sys.stdin
        sys.stdout, sys.stdin = StringIO(), StringIO(input)
        resolve()
        sys.stdout.seek(0)
        out = sys.stdout.read()[:-1]
        sys.stdout, sys.stdin = stdout, stdin
        self.assertEqual(out, output)
    def test_入力例_1(self):
        input = """12 4"""
        output = """4"""
        self.assertIO(input, output)
    def test_入力例_2(self):
        input = """20 15"""
        output = """0"""
        self.assertIO(input, output)
    def test_入力例_3(self):
        input = """20 30"""
        output = """0"""
        self.assertIO(input, output)

if __name__=="__main__":resolve()

Solution (Python):
a, b = map(int, input().split())
print(max(a - b*2, 0))

Solution (Python):
a,b = input().split()
a = int(a)
b = int(b)
ret = a - (b * 2)
if ret < 0:
    ret = 0
print(ret)

Solution (Python):
A,B=map(int,input().split())
print(max(0, A-2*B))

Solution (Python):
a,b=map(int,input().split())
if a-b*2<0:
  print('0')
else:
  print(a-b*2)

Solution (Python):
a, b = input().split()
print(max(0, int(a) - 2*int(b)))

Solution (Python):
def solve():
    N, M = map(int, input().split())
    return N - M*2 if N //2 >= M else 0

print(solve())

Solution (Python):
A, B = map(int, input().split())

print(max(0,A-2*B))

Solution (Python):
a,b = map(int, input().split())

print(max(a-2*b,0))

Solution (Python):
A,B = map(int, input().split())
if(B*2 >= A):
    print(0)
else:
    print(A-B*2)

Solution (Python):
A,B = map(int,input().split())

ans = A-B*2

if(ans>=0):
  print(ans)
else:
  print("0")

Solution (Python):
a,b=map(int,input().split())
if a-2*b>=0:
  print(a-2*b)
else:
  print(0)

Solution (Python):
A, B = map(int, input().split())

if B * 2 >= A:
  print(0)
else:
  print(A - B * 2)

Solution (Python):
a, b = map(int, input().split())
print(max(a - 2*b, 0))

Solution (Python):
i = list(map(int, input().split()))
o = i[0] - 2 * i[1]
if o <= 0:
  o = 0
print(o)

Solution (Python):
a,b = input().split()
a = int(a)
b = int(b)
if 0 < a-b*2:
  print(a-b*2)
else:
  print(0)

Solution (Python):
import sys

sys.setrecursionlimit(100000000)
input = lambda: sys.stdin.readline().rstrip()

A, B = map(int, input().split())
print(max(0, A - B * 2))

Solution (Python):



A, B = map(int, input().split())

if A<=B*2:
    print(0)
else:
    print(A-B*2)

Solution (Python):
a, b = map(int, input().split())
print(a-b*2 if a-b*2>= 0 else 0)

Solution (Python):
A,B = map(int,input().split())
if(A>=2*B):
    print(A-2*B)
else:
    print(0)

Solution (Python):
a, b = map(int, input().split())
print(max(0, a - b * 2))

Solution (Python):
a, b = map(int, input().split())
if a - b * 2 >= 0:
    print(a - b * 2)
else:
    print(0)

Solution (Python):
a,b = map(int, input().split())

s = a-2*b

if s>0:
  print(s)
else:
  print(0)