Problem:
 Score : 100 points    Problem Statement Find the number of ways to choose a pair of an even number and an odd number from the positive integers between 1 and K (inclusive). The order does not matter.      Constraints  2\leq K\leq 100  K is an integer.         Input Input is given from Standard Input in the following format:  K       Output Print the number of ways to choose a pair of an even number and an odd number from the positive integers between 1 and K (inclusive).        Sample Input 1 3      Sample Output 1 2  Two pairs can be chosen: (2,1) and (2,3) .       Sample Input 2 6      Sample Output 2 9       Sample Input 3 11      Sample Output 3 30       Sample Input 4 50      Sample Output 4 625

Solution (Python):
k=int(input())
a=0
b=0
if k%2==1:
    a=k//2+1
    b=k//2
else:
    a=k//2
    b=k//2
    
print(a*b)

Solution (Python):



k = int(input())
if k % 2 == 0:
    print((k // 2) * (k // 2))
else:
    print((k // 2) * (k // 2 + 1))

Solution (Python):
import math

K = int(input())
odd, even = math.ceil(K/2), math.floor(K/2)
print(odd * even)

Solution (Python):
N=int(input())
if N%2==1:
    n=int(int(N/2)+1)*int(N/2)
else:
    n=(N/2)*(N/2)
print(int(n))

Solution (Python):
k = int(input())
if k % 2 == 0:
    print((k//2) * (k//2))
else:
    print(((k-1)//2) * ((k-1)//2 + 1))

Solution (Python):
a = int(input())

if a % 2 == 0:
    
    even_num = a / 2
    odd_num = a / 2
else:
    even_num = (a - 1) / 2
    odd_num = (a - 1) / 2 + 1

ans = even_num * odd_num
print(int(ans))

Solution (Python):

import math
a = int(input())

f = 0
for ax in range(a):
   for bx in range(a):
       if ((ax + 1)% 2 == 0) and ((bx + 1)% 2 == 1):
           f = f+1
print(f)

Solution (Python):
K=int(input())
Ans=0
for i in range(1,K+1,2):
    for j in range(2,K+1,2):
        Ans+=1

print(Ans)

Solution (Python):

K = int(input())

evens = 0
odds = 0
for i in range(1,K+1):
    if i%2==0:
        evens+=1
    else:
        odds+=1
print(evens*odds)

Solution (Python):
K = int(input())

print(int(K/2)*(K-int(K/2)))

Solution (Python):
K = int(input())

print(int(K/2) * int(K/2 + 0.5))

Solution (Python):

from math import  floor, ceil
num = int(input())
if num %2==0:
    print(int(num/2)*int(num/2))
else:
    print(int(ceil(num/2)*floor(num/2)))

Solution (Python):
n=int(input())
print(int((n/2)**2))

Solution (Python):
def main():
    K = int(raw_input())
    odd = 0
    even = 0
    for i in range(1, K+1):
        if i % 2 == 0:
            even += 1
        else:
            odd += 1
    print even * odd

main()

Solution (Python):
K = int(input())

num_odd = K // 2 if K % 2 == 0 else K // 2 + 1
num_even = K // 2

print(num_odd * num_even)

Solution (Python):
k = int(input())

ans = 0
for i in range(k):
    if i % 2 == 1:
        e = False
    else:
        e = True

    for j in range(i + 1, k):
        if e and j % 2 == 1:
            ans += 1
        elif not e and j % 2 == 0:
            ans += 1

print(ans)

Solution (Python):
k = int(input())
result = 0
for i in range(0, k):
    if (i + 1) % 2 == 0:
        for j in range(0, k):
            if (j + 1) % 2 == 1:
                result += 1
print(result)

Solution (Python):
num = int(input())
if num % 2 == 0:
    print(int((num // 2)**2))
else:
    print(int((num // 2) * (num // 2 + 1)))

Solution (Python):
K = int(input())

if K % 2 == 0:
  print((K//2)**2)
else:
  print(((K-1)//2) * ((K+1)//2))

Solution (Python):
k = int(input())
ans = (k//2)**2
if k % 2 != 0:
  ans += (k//2)
print(ans)

Solution (Python):
k = int(input())

if k%2 == 0:
    m = k/2
    print(int(m*m))
else:
    m = (k-1)/2
    print(int(m*(m+1)))

Solution (Python):
K = int(input())

if K % 2 == 0:
    print(int((K/2)*(K/2)))
else:
    print(int(((K - 1) / 2) * ((K + 1)/2)))

Solution (Python):
k = int(input())
gu = 0
ki = 0
for i in range(1,k+1) :
    if i % 2 == 0 :
        gu += 1
    else :
        ki += 1
print(gu * ki)

Solution (Python):

k = int(input())

res = 0

if k % 2 == 0:
    res = k * k / 4
else:
    res = (k // 2) * (k // 2 + 1)

print(int(res))

Solution (Python):
K = int(input())
a = K // 2
if K%2 ==1:
    print(a * (a+1))
else:
    print(a ** 2)

Solution (Python):
k = int(input())
if k % 2 == 0:
    print(int(pow(k / 2, 2)))
else:
    k = k + 1
    print(int(pow(k / 2, 2) - k / 2))

Solution (Python):
K = int(input())
if K % 2 == 1:
    print((K//2)*(K//2+1))
else:
    print((K//2)*(K//2))

Solution (Python):
k = int(input())
even = int(k / 2)
odd = even
if k % 2 == 1:
    odd += 1
print(even * odd)

Solution (Python):
k = int(input())

if k % 2 == 0:
    print(int(k/2*k/2))
else:
    print(int((k//2+1)*(k//2)))

Solution (Python):
if __name__ == "__main__":
    k = int(input())
    count = 0
    for i in range(1, k+1):
        for j in range(1, k+1):
            if (i % 2 == 0 and j % 2 == 1 and i != j):
                count += 1


    print(count)

Solution (Python):
K = int(input())
n = K // 2
m = K % 2
if m:
    output = n * (n + 1)
else:
    output = n * n
print(output)

Solution (Python):
K = int(input())

if K % 2 == 1:
  print(int((K // 2) * ((K // 2) + 1)))
else:
  print(int((K/2)*(K/2)))

Solution (Python):
data = int(input())

if data%2 == 0:  
    ans = int(data/2) *int(data/2)
else:
    ans = int((data-1)/2) *int((data+1)/2)
print(ans)

Solution (Python):
K=int(input())
if K%2==0:
    m=(K/2)**2
else:
    m=((K-1)/2)*(((K-1)/2)+1)
n=int(m)
print(n)

Solution (Python):
K=input()
print (K/2)**2 if K%2==0 else (K/2)*(K/2+1)

Solution (Python):
k = int(input())

print(k//2 * -(-k//2))

Solution (Python):
k = int(input())
print(k // 2 * (k - k // 2))

Solution (Python):
k = int(input())
if k%2 == 0:
    print(int((k/2)**2))
else:
    l = (k-1)/2
    print(int(l*(k-l)))

Solution (Python):
k = int(input())
even = 0
odd = 0
if k % 2 == 0:
    even = k // 2
    odd = k // 2
else:
    even = k // 2
    odd = k // 2 + 1
print(even * odd)

Solution (Python):
k = int(input())

if k % 2 == 0:
    print(int(k**2/4))

if k % 2 != 0:
    k2 = (k+1)/2
    print(int(k2*(k2-1)))

Solution (Python):



def main():
    K = input()
    even = K / 2
    if K % 2 == 0:
        odd = even
    else:
        odd = even + 1

    print(odd * even)


if __name__ == "__main__":
    main()

Solution (Python):
K = int(input())
if K % 2 == 0:
    print((K // 2) ** 2)
else:
    print((K // 2) * ((K // 2) + 1))

Solution (Python):
a=int(input())

if a%2==0:
    print(int((a/2)**2))
else:
    print(int(int(a/2)*(int(a/2)+1)))

Solution (Python):
a=int(input())
if a%2:
	print(int(a//2*(a//2+1)))
else:
	print(int((a/2)**2))

Solution (Python):

K = int(input())

gusu = K // 2
kisu = K - gusu

print(kisu * gusu)

Solution (Python):
i = int(input())
if i%2==0:
    answer= int(i*i/4)
else:
    answer=i//2*(i//2+1)
print(answer)

Solution (Python):

"""
Created on Sat Sep  1 18:55:58 2018
ABC108A
@author: maezawa
"""

k = int(input())

if k%2 == 0:
    print((k//2)**2)
else:
    print((k//2)*(k//2+1))

Solution (Python):
K = int(input())

if K % 2 == 0:
    print((K // 2) * (K // 2))
else:
    print((K // 2) * (1 + K // 2))

Solution (Python):
p = int(input())
if p%2 == 0:
    print(int((p/2)**2))
else:
    print(int((p/2-1/2)*(p/2+1/2)))

Solution (Python):
n = int(input())
n1 = int(n/2)
n2 = n-n1
print(n1*n2)

Solution (Python):
a=int(input())
if a%2==0:
    print(int((a/2)*(a/2)))
else:
    print(int(((a+1)/2-1)*((a+1)/2)))

Solution (Python):
inp = int(input())
if inp % 2 == 0:
    print(int(inp*inp/4))
else:
    print(int((inp-1)*(inp+1)/4))

Solution (Python):
K = int(input())
a = K // 2
b = a + K % 2
print(a*b)

Solution (Python):


k = int(input())

if k % 2 == 0:
    print(int((k / 2) ** 2))
else:
    k2 = int(k / 2)
    print(int(k2 * (k2 + 1)))

Solution (Python):
K = int(input())

if K % 2 == 0:
    half = K//2
    ans = half**2
else:
    half = (K-1)//2
    ans = half * (half + 1)
print(ans)

Solution (Python):
K = int(input())
even = K // 2
odd = even + K % 2
print(even * odd)

Solution (Python):
K = int(input())

if K % 2 == 0:
	ans = (K // 2)**2
else:
	ans = (K//2)*(K//2 +1)
print(ans)

Solution (Python):
k = int(input())

if k%2==0:
    print((int(k/2))**2)
else:
    k = (k+1)//2
    print(k*(k-1))

Solution (Python):
n = input()
n = int(n)
k = n // 2
if n % 2 == 0:
    print(k*k)
else:
    print(k*(k+1))

Solution (Python):
K = int(input())
g = K // 2
k = K - g

print(g*k)

Solution (Python):
k = int(input())
if k % 2 == 1:
    print((k // 2) * (k // 2 + 1))
else:
    print((k // 2) ** 2)

Solution (Python):
from math import ceil, floor

K = int(input())

print(ceil(K/2) * floor(K/2))

Solution (Python):
a = int(input())
print((a//2) * ((a+1)//2))

Solution (Python):
import sys

ns = lambda: sys.stdin.readline().rstrip()
ni = lambda: int(ns())
na = lambda: [int(x) for x in ns().split()]
nall = lambda: [int(x) for x in sys.stdin.readlines()]

def main():
    k = ni()
    p = k // 2
    q = k - p
    print(p * q)

main()

Solution (Python):
n = int(input())
if n % 2 == 0:
    print(int((n/2)**2))
else:
    print(int((n//2)*(n//2 + 1)))

Solution (Python):
K = int(input())
if K % 2 == 0:
    print(int((K/2)*(K/2)))
else:
    print(int(((K+1)/2)*((K+1)/2-1)))

Solution (Python):
k=int(input())

a=int(k/2)
b=k-a

print(a*b)

Solution (Python):
x=int(input())
if(x%2==0):
	print(int((x/2)**2))
else:
	t=int((x+1)/2)
	print(t*(t-1))

Solution (Python):
K = int(input())
e,o = 0,0

if K%2:
    o = K//2 + 1
else:
    o = K//2
e = K//2

print(e*o)

Solution (Python):
K = int(input())

Ne = int(K/2.)
No = int((K+1)/2.)
print(Ne*No)

Solution (Python):


k = int(raw_input())

if k%2 == 0: kisu = k>>1
else: kisu = (k>>1) +1
gusu = k>>1

print kisu * gusu

Solution (Python):
K=int(input())

if K%2==0:
    print(int((K/2)**2))
else:
    print(int((K-1)/2*((K+1)/2)))

Solution (Python):
k = int(input())
if k%2 == 0:
    print((k//2)**2)
else:
    print((k//2)*((k//2)+1))

Solution (Python):
K = int(input())
print(int(K/2)*(int(K/2)+int(K%2)))

Solution (Python):
n = int(input())

def ceil(a,b):
	if a%b == 0:
		return a/b
	else:
		return a/b + 1

if n% 2 == 0:
	print (n/2 )**2

else :
	print n/2 * ((n/2)+1)

Solution (Python):
k = int(input())
print((int(k/2)*(int(k/2)+(k%2))))

Solution (Python):
na = lambda: list(map(int, input().split()))
k = int(input())
if k % 2 == 0: print((k//2)**2)
else: print((k//2)*((k//2)+1))

Solution (Python):
k = int(input())
count = 0
for i in range(1, k+1):
    for j in range(1, k+1):
        if i % 2 == 0:
            if j % 2 == 1:
                count = count + 1
print(count)

Solution (Python):
K = int(input())
print((K // 2) ** 2 if K % 2 == 0 else ((K // 2) + 1) * (K // 2))

Solution (Python):
K = int(input())
print(int(K//2)*int((K+1)//2))

Solution (Python):
k = int(input())
j = k&1
l = k>>1
print(l*(l+j))

Solution (Python):
K = int(input())
cnt = 0

for i in range(2, K+1, 2):
    for j in range(1, K+1, 2):
        cnt += 1

print(cnt)

Solution (Python):
k = int(input())
if k%2 == 0:
    print((k//2)*(k//2))
else:
    print((k//2+1)*(k//2))

Solution (Python):
def solve(N):
    return int(N / 2) * int((N + 1) / 2)

if __name__ == "__main__":
    l = input()
    N = int(l)
    print(solve(N))

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

n = int(input())
if n%2 == 0:
    print(int(n*n/4))
    exit()
else:
    print(int(n//2*(n//2+1)))

Solution (Python):

import sys
import math
import numpy as np
import itertools

k = int(input())

print( (k//2) * ((k+1)//2) )

Solution (Python):



def main():
    k = int(input())

    if k % 2 != 0:
        print(k // 2 * (k + 1) // 2)
    else:
        print((k // 2) ** 2)


if __name__ == '__main__':
    main()

Solution (Python):
K=int(input())
if (K%2==0):
    print(int((K/2)**2))
else:
    print(int((K+1)/2*(K-1)/2))

Solution (Python):
k=int(input())

if k%2==1:
  nodd=int(k/2)+1
  neven=int(k/2)
else:
  nodd=int(k/2)
  neven=int(k/2)
print(nodd*neven)

Solution (Python):
k = int(input())

if k % 2 == 0:
    print((k // 2 ) ** 2)
else:
    print((k // 2) * ((k+1) // 2))

Solution (Python):
k = int(input())

if k % 2 == 0:
    print(int(k/2) ** 2)
else:
    print(int((k-1)/2) * (int((k-1)/2)+1))

Solution (Python):
k = int(input())
if k % 2 ==0:
    n = k // 2
    print(n**2)
else:
    n = k // 2
    print(n * (n+1))

Solution (Python):

def solve():
    k = int(input())
    o = (k>>1) + (k&1)
    e = k>>1
    return str(o*e)

if __name__ == '__main__':
    print(solve())

Solution (Python):
K = int(input())

a = K // 2

b = K - a

print(a * b)

Solution (Python):
k=int(input())
if k%2==0:
    print((k//2)**2)
else:
    print((k//2)*(k//2+1))

Solution (Python):
K = int(input())

if K % 2 == 0:
	out = int((K/2)**2)
	print(out)
else:
	out = int((K-1)*(K+1)/4)
	print(out)

Solution (Python):
k = int(input())
count = 0
for i in range(k):
    for j in range(i+1, k):
        if (i % 2 == 0 and j % 2 == 1) or (i % 2 == 1 and j % 2 == 0):
            count +=1
print(count)

Solution (Python):
a = int(input())
print(a//2*(a-a//2))

Solution (Python):
K = int(input())
if K % 2 != 0 :
    print(K//2*(K//2+1))
else :
    print((K//2)**2)

Solution (Python):
K = int(input())
odd = 0
even = 0
for i in range(1, K + 1):
	if i % 2 == 0:
		even += 1
	else:
	 odd += 1
print(odd * even)

Solution (Python):
a = int(input())
if a%2 == 0:
    print((a//2) ** 2)
else:
    b = a//2
    print(b*(b+1))

Solution (Python):
K=int(input())
if K%2==0:
    print(int(K/2)**2)
else:
    print(int((K+1)/2)*int((K-1)/2))

Solution (Python):
k = int(input())

a = (k+1)//2
b = k//2

print(a*b)

Solution (Python):
N = int(input())
a =N//2
b = (N+1)//2

print(a*b)

Solution (Python):
k = int(input())

odd = (k+1)//2
even = k//2
print(odd*even)

Solution (Python):
N = int(input())
print(int((N/2)**2))

Solution (Python):
K = int(input())
print((K // 2) * (K - K // 2))

Solution (Python):
k = int(input())
t = k//2
if k % 2 == 0:
    print(t ** 2)
else:
    print(t*(t+1))

Solution (Python):

def abc108_a():
    import sys
    input = sys.stdin.readline

    k = int(input())
    if k % 2 == 0:
        return int(k ** 2 / 4)
    else:
        return int((k // 2) * (k // 2 + 1))


print(abc108_a())

Solution (Python):
K = int(input())

print((K // 2) ** 2 + (K % 2) * (K // 2))

Solution (Python):
import math
k = input()

k = int(k)

even = math.floor(k/2)
odd = even if k % 2 == 0 else even + 1

print(even * odd)

Solution (Python):
k = int(input())
if k%2:
    ans = (k//2+1)*(k//2)
else:
    ans = (k//2)**2
print(ans)

Solution (Python):
K = int(input())

if K % 2 == 0:
	print((K // 2) ** 2)
else:
	print((K//2) * (K//2 + 1))

Solution (Python):
K = int(input())

gusu = K // 2
odd = K - gusu

print(gusu*odd)

Solution (Python):
k=int(input())
if k%2==0:
  print(k*k//4)
else:
  print((k*k-1)//4)

Solution (Python):
n=int(input())
if n%2==0:
    print((n//2)*(n//2))
else:
    print((n//2)*(n//2+1))

Solution (Python):
N = int(input())

if (N%2 == 0):
    print(int(N/2*N/2))
else:
    print(int((N-1)/2*(N+1)/2))

Solution (Python):
K = int(input())
l = list(range(1, K+1))
a = list(filter(lambda x: x%2, l))
b = list(filter(lambda x: not x%2, l))
print(len(a)*len(b))

Solution (Python):
K = int(input())

num = [i for i in range(1, K+1)]

kisuu = num[0::2]
guusuu = num[1::2]

ans = len(kisuu) * len(guusuu)

print(ans)

Solution (Python):
K = int(input())
a = K // 2
b = K - a
ans = a * b

print(ans)

Solution (Python):
a=int(input())
print((a//2)*((a+1)//2))

Solution (Python):
k = int(input())

if (k % 2 == 0):
    print(int((k/2)*(k/2)))
else:
    print(int(((k//2)+1)*(k//2)))

Solution (Python):
K = int(input())
if K % 2 == 0:
    re = (K // 2) ** 2
else:
    re = (K // 2) * (K // 2 + 1)
print(re)

Solution (Python):
import math
K=int(input())

print((K//2)*(math.ceil(K/2)))

Solution (Python):
K = int(input())
odd = 0
if K%2==1:
    odd = 1
print((K//2+odd)*(K//2))

Solution (Python):
i = int(input())

print((i//2)*((i+1)//2))

Solution (Python):
K = int(input())
ans = 0
for i in range(1, K):
    for j in range(i+1, K+1):
        if i % 2 and j % 2 == 0:
            ans += 1
        elif i % 2 == 0 and j % 2:
            ans += 1
print(ans)

Solution (Python):
k=int(input())
if k%2==0:
    print(int((k/2)**2))
else:
    print(int(((k-1)/2+1)*(k-1)/2))

Solution (Python):
K = int(input())

a = K // 2

b = K // 2 + K % 2

print(a*b)

Solution (Python):
K = int(input())

g = K // 2
k = K - g

print(g * k)

Solution (Python):
K = int(input())

odd = [i for i in range(1, K+1) if i % 2 != 0]
even = [i for i in range(1, K+1) if i % 2 == 0]

print(len(odd) * len(even))

Solution (Python):
a = int(input())
b = a-a//2
print(a//2*b)

Solution (Python):
K = int(input())
if K % 2 == 0:
    print((K//2) ** 2)
else:
    print((K//2) * ((K+1)//2))

Solution (Python):
k = int(input())
a = k//2
b = k -a

ans = a * b
print(ans)

Solution (Python):
N = int(input())

if N % 2 == 0:
  print((N // 2) ** 2)
else:
  print((N // 2) * (N // 2 + 1))

Solution (Python):
K = int(input())

if K % 2 == 0:
    x = K // 2 
    y = K // 2
else:
    x = K // 2
    y = K // 2 + 1

print(x * y)

Solution (Python):
K = int(input())

if K % 2 == 0:
    print((int(K / 2))**2)

else:
    kk = (K-1)/2
    print(int(kk * (kk+1)))

Solution (Python):
K=int(input())

print((K//2)*(K-K//2))

Solution (Python):
K = int(input())
o = (K + 1) // 2
e =  K      // 2
print(o * e)

Solution (Python):
K = int(input())
gusu = K // 2
kisu = K -gusu
print(gusu * kisu)

Solution (Python):
k=int(input())
a=k//2
b=k-a
print(int(a*b))

Solution (Python):
k=int(input())
print(k//2*(k//2+k%2))

Solution (Python):
K=int(input())
e=K//2
o=(K+1)//2
print(e*o)

Solution (Python):
K = int(input())

odd = K // 2 + K % 2
even = K // 2

print(odd * even)

Solution (Python):
n = int(input())
a = int(n / 2)
b = a + n%2
print(a * b)

Solution (Python):





def main(k):
    kinum = int(k/2) + k%2
    gunum = int(k/2)
    print(kinum * gunum)
    
if __name__ == '__main__':
    try:
        k = int(input().strip())
        main(k)
    except EOFError:
        pass

Solution (Python):
k = int(input())
x = k // 2
y = (k + 1) // 2
print(x * y)

Solution (Python):
K = int(input())

if K % 2 == 0:
    print((K//2)**2)
else:
    print((K//2)*(K//2 + 1))

Solution (Python):
K=int(input())
e=K//2
o=(K+1)//2
print(e*o)

Solution (Python):
K = int(input())
even = K//2
odd = K - even
print(even*odd)

Solution (Python):
K = int(input())

e = int((K + 1)/2)
o = int(K/2)

print(e*o)

Solution (Python):
import math
k=int(input())
p=k//2
q=math.ceil(k/2)
print(p*q)

Solution (Python):


import math

INF = float('inf')


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


n = int(input())

print(math.ceil(n/2) * math.floor((n/2)))

Solution (Python):
n = int(raw_input())
if n % 2 == 0:
    print (n/2)*n/2
else:
    print n/2*(n/2+1)

Solution (Python):
k = int(input())

if k%2==0:
    print((k//2)**2)
else:
    print((k//2)*(k//2+1))

Solution (Python):
import math
n = int(input())
if n % 2 == 1:
  print(math.floor(n/2) * math.ceil(n/2))
else:
  print(int(n/2) ** 2)

Solution (Python):
k = input()
even = k/2
odd = k-k/2
print even*odd

Solution (Python):
K=int(input())

a=K//2
b=K-a

print(a*b)

Solution (Python):
K = int(input())
print((K // 2) * (K - K // 2))

Solution (Python):
n = int(input())
if n%2 == 0:
    print((n//2)**2)
else:
    print((n//2)*(n//2+1))

Solution (Python):
def iin(): return int(input())
def nl(): return list(map(int, input().split()))
def ary(r, c, v): return [[v for _ in range(c)] for _ in range(r)]

k = iin()
if k % 2 == 0:
    ans = (k // 2) ** 2
else:
    ans = (k // 2) * (k // 2 + 1)
print(ans)

Solution (Python):
k = int(input())

a = k // 2
b = k // 2 + k % 2

print(a * b)

Solution (Python):
n=int(input())

even=int(n/2)
if n%2==0:
    odd=even
else:
    odd=even+1

print(odd*even)

Solution (Python):
k = int(input())
if k % 2 == 0:
  r = (k//2)*(k//2)
else:
  r = (k//2)*((k//2)+1)
print(r)

Solution (Python):
n = int(input())

if n%2 == 1:
    odd = (n + 1)/2
    even = (n - 1)/2
else:
    odd = n/2
    even = n/2
ans = odd * even
print(int(ans))

Solution (Python):
K = int(input())

x = int(K / 2)
y = K - x

print(x * y)

Solution (Python):
n = int(input())
print(n//2 * (n - n//2))

Solution (Python):
n=int(input())
a=n//2
print((n-a)*a)

Solution (Python):
k = int(input())
if k%2 ==1:
    k1 = k//2
    k2 = k1+1
    print(k1*k2)
    
else:
    print(int(k/2)**2)

Solution (Python):
n=int(input())

print((n//2)*((n+1)//2))

Solution (Python):
k = int(input())

if k % 2 == 1:
	print((k//2)*(k//2+1))
else:
	print((k//2)**2)

Solution (Python):

K = int(input())
print((K // 2) * (K - (K // 2)))

Solution (Python):
k = int(input())

even = k//2;

odd = k - even;

print(odd*even)

Solution (Python):
k=int(input())

if k%2==1:
    print((k//2)*(k//2+1))
else:
    print((k//2)**2)

Solution (Python):
n = int(input())
tmp = n //2
tmp2 = n-tmp
print(tmp*tmp2)

Solution (Python):
K = int(input())
kisu = K // 2 + K % 2
gusu = K // 2
print(kisu * gusu)

Solution (Python):
K = int(input())

print(int((K//2) * (K//2 + K%2)))

Solution (Python):
k = int(input())
print((k//2*(-(-k//2))))

Solution (Python):
k=int(input())
a=k//2
b=k-a
print(a*b)

Solution (Python):
k=int(input())

ans=0
for i in range(k):
    for j in range(k):
        if i%2==0 and j%2==1:
            ans+=1
print(ans)

Solution (Python):
import math
k = int(input())
print((k // 2) * math.ceil(k / 2))

Solution (Python):
k=int(input())
h=int(k/2)

print((k-h)*h)

Solution (Python):
n=int(input())
x1=n//2
x2=(n+1)//2
print(x1*x2)

Solution (Python):
k = int(input())
a = 0
b = 0
for i in range(1, k+1):
    if i % 2 == 0:
        a += 1
    else:
        b += 1
print(a * b)

Solution (Python):
k = int(input())
a = (k+1)//2
b = k//2
print(a*b)