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

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

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

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

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

Solution (Python):

[A,B] = list(map(int,input().split()))

nokori = A - B*2

if nokori>=0:
    print(nokori)

else:
    print(0)

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

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

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

print(ans)

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

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

    result = A - B * 2

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

if __name__ == "__main__":
    main()

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

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

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

Solution (Python):
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 < 0:
    print(0)
else:
    print(a-b*2)

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

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

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

Solution (Python):

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

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

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

Solution (Python):
input_line = input()
inputs = input_line.split(' ')
inputs = [int(input) for input in inputs]

A = inputs[0]
B = inputs[1]

dual_B = 2 * B

res = 0
if A > dual_B:
    res = A - dual_B
else:
    res = 0

print(res)

Solution (Python):
def main():
    
    n,k= map(int, input().split())
    p=n-2*k
    print(p) if p>0 else print(0)
    return
main()

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

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

else:
    nokori = a - 2*b
    print(nokori)

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

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

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

Solution (Python):
print(max(0,eval(input().replace(' ','-2*'))))

Solution (Python):
print(max(0,eval(input().replace(' ','-')+'*2')))

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

else:
    print(0)

Solution (Python):
input_l = input().rstrip().split(' ')
input_l = list(map(int,input_l))

if(input_l[0] > input_l[1] * 2):
    print(input_l[0]-input_l[1]*2)
else:
    print(0)

Solution (Python):
A, B = map(int, input().split())
ans = 0

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

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

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

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

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

Solution (Python):
from sys import stdin

a, b = [int(x) for x in stdin.readline().rstrip().split()]
print(a - 2*b if a-2*b > 0 else 0)

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

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

ans = a - b * 2

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

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

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

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

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

ans = a - b * 2

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

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

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

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

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

Solution (Python):
A, B = [int(x) for x in input().split(" ")]

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

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

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

Solution (Python):





import sys

input = sys.stdin.readline
MOD = 10 ** 9 + 7
INF = float('INF')
sys.setrecursionlimit(10 ** 5)


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

if __name__ == '__main__':
    main()

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

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

uncovered = A-B-B

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

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

Solution (Python):
import sys

read = sys.stdin.buffer.read
input = sys.stdin.buffer.readline
inputs = sys.stdin.buffer.readlines






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

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

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

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

Solution (Python):
from itertools import accumulate, permutations, combinations, product, combinations_with_replacement
from math import floor, ceil, sqrt, factorial, log
from bisect import bisect_left, bisect_right
from collections import Counter, defaultdict
from heapq import heappop, heappush, heappushpop
from itertools import product
import sys
stdin = sys.stdin
mod = 10**9 + 7


def ns(): return stdin.readline().rstrip()


def ni(): return int(ns())


def na(): return list(map(int, stdin.readline().split()))


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

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

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

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

Solution (Python):
if __name__ == "__main__":
    a, b = map(int, input().split())

    if a - b * 2 <= 0:
        print('0')
    else:
        print(str(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 - 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())
print(max(0, a - 2 * b))

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

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

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


if __name__ == '__main__':
    main()

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

if num[1]*2 > num[0]:
  ans = 0
elif num[1]*2 <= num[0]:
  ans = - num[1]*2 + num[0]
  
print(ans)

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

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

Solution (Python):



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

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

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

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

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

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

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())

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

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

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

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

Solution (Python):


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

if __name__ == '__main__':
  main()

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

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

print(R)

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 > 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())

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):
curtain = input().split(" ")
A = int(curtain[0])
B = int(curtain[1])
if B * 2 >= A:
	print(0)
else:
	print(A - (B * 2))

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

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

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

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

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

if A < B*2:
    print("0")
else:
    print(int(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(max(a-2*b,0))

Solution (Python):


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

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

if A < B*2:
    print(0)

elif A >= B*2:
    print(A-B*2)

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

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

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

ans = a-b*2
print(ans if ans > 0 else 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())
print(max(0, A-(B*2)))

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

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

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

Solution (Python):
A,B=(int(i) for i in input().split())


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

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

Solution (Python):



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

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

if a >= b:
    ans = a - b

print(ans)

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

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

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

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

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

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

ans = a - b * 2

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

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

ans = a - 2*b

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

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-2*b, 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())  
print(max(a - b * 2, 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 b*2 >= a:
  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):
A,B = (int(x) for x in input().split())
print(max(A - 2 * B, 0))

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

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

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 - b * 2)

Solution (Python):
a, b = map(int, input().split())
ans = 0

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

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

Solution (Python):
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def IS(): return sys.stdin.readline()[:-1]
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LII(rows_number): return [II() for _ in range(rows_number)]
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]

def main():
	A,B = MI()
	if(A <= B*2):
		print(0)
	else:
		print(A-2*B)

main()

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

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

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
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()))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

A, B = MAP()

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

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

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

Solution (Python):

import sys
input = sys.stdin.buffer.readline


from collections import defaultdict

con = 10 ** 9 + 7

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


def main():
	A, B = getlist()
	if 2 * B >= A:
		print(0)
	else:
		print(A - 2 * B)
		
	


if __name__ == '__main__':
	main()

Solution (Python):




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


if __name__ == "__main__":
    main()

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

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

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

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

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

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

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

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

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

if __name__ == '__main__':
    main()

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

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 >= 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(a-2*b,0))

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

Solution (Python):
import sys
input=sys.stdin.readline
n,m=map(int,input().split())
print(0 if n<=m*2 else n-m*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 <= B * 2 : print(0)
else : print(A - B * 2)

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

Solution (Python):
width = input().split(" ")
curtain_width = 2 * int(width[1])
window_width = int(width[0])
uncovered = window_width - curtain_width
if uncovered <= 0:
    print("0")
else:
    print(uncovered)

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-2*b, 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 - 2*b > 0:
    print(a-2*b)
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):
x = input().split()
A,B = [int(i) for i in x]
d = A - 2*B
if d<0:
  d = 0
print(d)

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

x = a-b*2

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

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

def read_ints(row):
    return list(map(int, row().split()))

A,B = read_ints(row)

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

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

Solution (Python):
import sys


def solve(inp):
    (A, B) = map(int, inp.readline().strip().split(' '))

    r = A - B * 2
    if r < 0:
        r = 0

    return str(r)


def main():
    result = solve(sys.stdin)
    if result:
        print(result)


if __name__ == '__main__':
    main()

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(A-B*2,0))

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

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

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

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())
x=A-(B*2)
if x>=0:
  print(x)
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())
print(max(0, a - 2*b))

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

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

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

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

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

Solution (Python):

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

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

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

Solution (Python):


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

res = A - 2 * B

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

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

Solution (Python):
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())
print(max(a - 2 * b, 0))

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

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

if (2 * b) > a:
    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())

uncovered_space = A - 2 * B

if uncovered_space > 0:
    print(uncovered_space)
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):
import sys, re, os
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import permutations, combinations, product, accumulate
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from fractions import gcd
 
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def S_MAP(): return map(str, input().split())
def LIST(): return list(map(int, input().split()))
def S_LIST(): return list(map(str, input().split()))
 
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

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

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

Solution (Python):
A, B = list(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())
if A-2*B<=0:
    print(0)
else:
    print(A-2*B)

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

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

print(res)

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())
C = A - 2*B

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