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):






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

        res = 0

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


if __name__ == '__main__':
    Solution().main()

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

Solution (Python):
import bisect
import heapq
import itertools
import math
import operator
import os
import re
import string
import sys
from collections import Counter, deque, defaultdict
from copy import deepcopy
from decimal import Decimal
from fractions import gcd
from functools import lru_cache, reduce
from operator import itemgetter, mul, add, xor

import numpy as np

if os.getenv("LOCAL"):
    sys.stdin = open("_in.txt", "r")

sys.setrecursionlimit(2147483647)
INF = float("inf")
IINF = 10 ** 18
MOD = 10 ** 9 + 7



A, B = list(map(int, sys.stdin.readline().split()))
a = A - B * 2
print(max(a, 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(0)
else:
    print(a - b*2)

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

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

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

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

Solution (Python):
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time
sys.setrecursionlimit(10**7)
inf = 10**20


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

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

Solution (Python):
from collections import defaultdict,deque
import sys,heapq,bisect,math,itertools,string,queue,copy,time
sys.setrecursionlimit(10**8)
INF = float('inf')
mod = 10**9+7
eps = 10**-7
def inp(): return int(sys.stdin.readline())
def inpl(): return list(map(int, sys.stdin.readline().split()))
def inpl_str(): return list(sys.stdin.readline().split())

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

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

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

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

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

Solution (Python):
ni = lambda: int(input())
nm = lambda: map(int, input().split())
nl = lambda: list(map(int, input().split()))


a, b = nm()

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

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

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

Solution (Python):
A, B = list(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 = list(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(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(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())
print(max(A-2*B,0))

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

print(max(ans,0))

Solution (Python):
a,b = input().split()
a = int(a)
b = int(b)
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):
import sys
a, b = [int(i) for i in sys.stdin.readline().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 * 2))

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(0,A-B-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(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):
import sys
def get_array(): return list(map(int , sys.stdin.readline().strip().split()))
def get_ints(): return map(int, sys.stdin.readline().strip().split())
def input(): return sys.stdin.readline().strip()

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

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

Solution (Python):










import sys
import os
from io import IOBase, BytesIO


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


BUFSIZE = 8192


class FastIO(BytesIO):
    newlines = 0

    def __init__(self, file):
        self._file = file
        self._fd = file.fileno()
        self.writable = "x" in file.mode or "w" in file.mode
        self.write = super(FastIO, self).write if self.writable else None

    def _fill(self):
        s = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
        self.seek((self.tell(), self.seek(0, 2), super(FastIO, self).write(s))[0])
        return s

    def read(self):
        while self._fill():
            pass
        return super(FastIO, self).read()

    def readline(self):
        while self.newlines == 0:
            s = self._fill()
            self.newlines = s.count(b"\n") + (not s)
        self.newlines -= 1
        return super(FastIO, self).readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.getvalue())
            self.truncate(0), self.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        py2 = round(0.5)
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        if py2 == 1:
            self.write = self.buffer.write
            self.read = self.buffer.read
            self.readline = self.buffer.readline
        else:
            self.write = lambda s: self.buffer.write(s.encode("ascii"))
            self.read = lambda: self.buffer.read().decode("ascii")
            self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)


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


def get_ints():
    return map(int, sys.stdin.readline().split())


def input():
    return sys.stdin.readline().strip()


if __name__ == "__main__":
    main()

Solution (Python):

import sys
input = lambda: sys.stdin.readline()[:-1]
sys.setrecursionlimit(10**8)

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

Solution (Python):
from fractions import gcd
from datetime import date, timedelta
from heapq import*
import math
from collections import defaultdict, Counter, deque
import sys
from bisect import *
import itertools
import copy
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7


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

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

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

Solution (Python):

import sys
INF = float("inf")


def solve(A: int, B: int):
    print(max(A-2*B, 0))
    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 b * 2 >= a:
    print(0)
else:
    print(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(A - 2 * B, 0))

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

Solution (Python):
def slove():
    import sys
    input = sys.stdin.readline
    a, b = list(map(int, input().rstrip('\n').split()))
    print(max(a - b * 2, 0))


if __name__ == '__main__':
    slove()

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

if __name__ == '__main__':
    solve()

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

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(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())
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=[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())
print(max(0,a-b-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):
import sys
import math
from collections import defaultdict

sys.setrecursionlimit(10**7)
def input():
    return sys.stdin.readline()[:-1]

mod = 10**9 + 7

def I(): return int(input())
def II(): return map(int, input().split())
def III(): return list(map(int, input().split()))
def Line(N,num):
    if N<=0:
        return [[]]*num
    elif num==1:
        return [I() for _ in range(N)]
    else:
        read_all = [tuple(II()) for _ in range(N)]
        return map(list, zip(*read_all))



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

Solution (Python):

import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline

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(0, a - 2*b))

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

Solution (Python):
import sys

stdin = sys.stdin

ns = lambda : stdin.readline().rstrip()
ni = lambda : int(ns())
na = lambda : list(map(int, stdin.readline().split()))

def main():
    a, b = na()

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

main()

Solution (Python):
import sys
from heapq import heappop, heappush
from operator import itemgetter
from collections import deque, defaultdict, Counter
from bisect import bisect_left, bisect_right
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10**9 + 7
INF = float('inf')

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


sol()

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

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

Solution (Python):
import sys
sys.setrecursionlimit(2147483647)
INF=float("inf")
MOD=10**9+7

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

Solution (Python):

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