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):
import sys
 
stdin = sys.stdin
inf = 1 << 60
mod = 1000000007
 
ni = lambda: int(ns())
nin = lambda y: [ni() for _ in range(y)]
na = lambda: list(map(int, stdin.readline().split()))
nan = lambda y: [na() for _ in range(y)]
ns = lambda: stdin.readline().rstrip()
nsn = lambda y: [ns() for _ in range(y)]
ncl = lambda y: [list(ns()) for _ in range(y)]
nas = lambda: stdin.readline().split()

K = ni()

e, o = 0, 0
ans = 0
for i in range(1, K + 1):
    if i % 2 == 0:
        e += 1
        ans += o
    elif i % 2 == 1:
        o += 1
        ans += e

print(ans)

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

Solution (Python):
print(input()**2//4)

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

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

Solution (Python):
print(int(input())**2//4)

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

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

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

tmp = 0
while True:
	tmp += (K // 2)
	K = K - 1
	if (K == 0):
		break

print(tmp)

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

Solution (Python):

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

Solution (Python):
import sys

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



K = [int(_) for _ in input().split()][0]
g = k = K // 2
if K % 2 == 1:
    k += 1
print(g * k)

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

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

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

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

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

k = K//2 + 1 if K%2==1 else K//2

print((K//2)*k)

Solution (Python):
from itertools import product
K = int(input())
even = [x for x in range(1, K+1) if x % 2 == 0]
odd = [x for x in range(1, K+1) if x % 2 != 0]
print(len(list(product(even, odd))))

Solution (Python):
k=int(input())
t=k%2
if t==0:
  print(int(k*k/4))
else:
  a=k//2
  a=a*a+a
  print(a)

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

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

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

print(a*b)

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

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

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

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

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

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

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

a = int(k/2)

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

print(o*a)

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

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

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

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


if __name__ == '__main__':
    solve()

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

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

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

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

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

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

Solution (Python):
def main():
    K = int(input())
    even = 0
    odd = 0
    if K % 2 == 0:
        even = K // 2
        odd = K // 2
    else:
        even = (K - 1) // 2
        odd = K - even
    print(even * odd)


if __name__ == '__main__':
    main()

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

odd, even = 0, 0
if k % 2 == 0:
  odd = k // 2
  even = odd
else:
  even = (k - 1) // 2
  odd = even + 1

print(even * odd)

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

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

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

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

Solution (Python):
def main():
  n = int(input())
  a = n // 2
  b = (n + 1) // 2
  print(a*b)
  
if __name__ == "__main__":
  main()

Solution (Python):
def saiki(k) :
    if k == 1 :
        return 0
    if k == 2 :
        return 1
    return saiki(k - 2) + k - 1

K = int(input())
print(saiki(K))

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

Solution (Python):




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


if __name__ == "__main__":
    main()

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

print(even*odd)

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

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

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

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

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

print(ans)

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

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

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

Solution (Python):
K = int(input())
K1 = K // 2
K2 = K - K1
print(K1 * K2)

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

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

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

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

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

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

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

Solution (Python):
import itertools

K = int(input())

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

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

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

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

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

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

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

Solution (Python):
n=int(input())
q,r=divmod(n,2)
print(q*(q+r))

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

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

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

for i in range(1, K+1):
  if i%2==0:
    
    for i in range(1, K+1):
        if i%2==1:
            
            count +=1

print(count)

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

Solution (Python):

import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
n = int(input())
print((n-n//2)*(n//2))

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

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

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

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

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

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

Solution (Python):
print(int(input())**2//4)

Solution (Python):
"""
author : halo2halo
date : 23, Jan, 2020
"""

import sys



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

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

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

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

Solution (Python):
import sys
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
def input(): return sys.stdin.readline().rstrip()

def main():
    K=int(input())
    print(K//2*(-(-K//2)))

if __name__ == '__main__':
    main()

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

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())
print((a//2)*(a-a//2))

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

Solution (Python):
n=int(input())
g=n//2
k=(n+1)//2
print(k*g)

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

Solution (Python):
print(int(input())**2>>2)

Solution (Python):
K = int(input())
ans = len(range(1, K+1, 2)) * len(range(2, K+1, 2))
print(ans)

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

ans = (K // 2) * -(-K // 2)

print(ans)

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

Solution (Python):
K = int(input())
L = list(range(1, K))
n = (K // 2)
if K % 2 == 0:
    print(n**2)
else:
    print(n * (n + 1))

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

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

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

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

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

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

Solution (Python):
def main():
    from sys import stdin, setrecursionlimit
    setrecursionlimit(10**6)
    
    n = int(stdin.readline()[:-1])   
    
    

    from math import ceil,floor
    print(ceil(n/2)*floor(n/2))

if __name__ == '__main__':
    main()

Solution (Python):
import sys
from math import ceil

INPUT = lambda: sys.stdin.readline().rstrip()
INT = lambda: int(INPUT())

sys.setrecursionlimit(10 ** 9)


def main():
    K = INT()
    print((K//2)*ceil(K/2))


if __name__ == '__main__':
    main()

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

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

Solution (Python):
N=int(input())
if N%2==0:
  print(int(N/2)**2)
elif N%2!=0:
  print((N//2)*(N-(N//2)))

Solution (Python):
N=int(input())
if N%2==0:
  print((N//2)**2)
elif N%2!=0:
  print((N//2)*(N-(N//2)))

Solution (Python):
import math
import queue
import bisect
import heapq
import time
import itertools

mod = int(1e9+7)

def swap(a,b):
    return (b,a)

def my_round(a,dig=0):
    p = 10 ** dig
    return (a * p * 2 + 1) // 2 / p

def gcd(a,b): 
    if (a<b):
        a,b = swap(a,b)
    if (b==0):
        return a
    else:
        return gcd(b,a%b)

def lcm(a,b): 
    return a/gcd(a,b)*b

def divisors(a): 
    divisors = []
    for i in range(1,int(a**0.5)+1):
        if a%i==0:
            divisors.append(i)
            if i!=a//i:
                divisors.append(a//i)
    return divisors

def is_prime(a): 
    if a<2:
        return False
    elif a==2:
        return True
    elif a%2==0:
        return False
    sqrt_num = int(a**0.5)
    for i in range(3,sqrt_num+1,2):
        if a%i==0:
            return False
    return True

def prime_num(a): 
    pn = [2]
    for i in range(3,int(a**0.5),2):
        prime = True
        for j in pn:
            if i%j==0:
                prime = False
                break
        if prime:
            pn.append(i)
    return pn

def prime_fact(a): 
    sqrt = math.sqrt(a)
    res = []
    i = 2
    if is_prime(a):
        res.append(a)
    else:
        while a!=1:
            while a%i==0:
                res.append(i)
                a //= i
            i += 1
    return res

def main():
    k = int(input())
    even = k // 2
    odd = k - even
    print(even*odd)
    return

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

Solution (Python):
import sys

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

    odd = K // 2
    even = K - odd

    print(odd * even)

main()

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

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

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

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

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

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

Solution (Python):
import math

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

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

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

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

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

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

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

print(len(range(2, K+1, 2)) * len(range(1, K+1, 2)))

Solution (Python):
print(int(input())**2//4)

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

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

if n%2 == 0:
  print((n//2)**2)
elif n > n//2*2:
  print(n//2*(n//2+1))
else:
  print(n//2*(n//2-1))

Solution (Python):
import sys

k = int(sys.stdin.readline().rstrip())

def main():
    return (k - k // 2) * (k // 2)

if __name__ == '__main__':
    ans = main()
    print(ans)

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

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

l = []

for x in range(1, a + 1):
  for y in range(1, a + 1):
    if (x % 2 == 0) and (y % 2 == 1):
      l.append([x, y])

print(len(l))

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

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

print(int(ans))

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

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

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

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

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

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

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

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

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

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

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

even = k // 2
odd = k - even

print(even*odd)

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

Solution (Python):
import sys
input = sys.stdin.readline
K = int(input())
d = K //2
dk = K - d
print(d * dk)

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

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

Solution (Python):
import bisect
import cmath
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(10 ** 9)
INF = float("inf")
IINF = 10 ** 18
MOD = 10 ** 9 + 7


k = int(sys.stdin.buffer.readline())
if k % 2 == 0:
    ans = ( k // 2 ) ** 2

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

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

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

Solution (Python):

import math

k = int(input())

odd = math.ceil(k/2)
even = math.floor(k/2)

print(odd * even)

Solution (Python):
import sys, math
def input():
    return sys.stdin.readline()[:-1]
from itertools import permutations, combinations
from collections import defaultdict, Counter

sys.setrecursionlimit(10**7)
N = int(input())

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

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

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

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

o = k//2
e = k - k//2
print(o*e)

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

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

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

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

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

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

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

print(ans)

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

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

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

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

ans = 0

for i in range(1,K):
    for j in range(i+1,K+1):
        if (i % 2 == 0 and j % 2 == 1) or (i % 2 == 1 and j % 2 == 0):
            ans += 1

print(ans)

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):
k = int(input())
ans = (k//2) * ((k+1)//2)
print(ans)

Solution (Python):
INT = lambda: int(input())
INTM = lambda: map(int,input().split())
STRM = lambda: map(str,input().split())
STR = lambda: str(input())
LIST = lambda: list(map(int,input().split()))
LISTS = lambda: list(map(str,input().split()))
def do():
    n=INT()
    if n%2==0:
        print(int(n*n/4))
    else:
        print((n//2)*(n//2+1))
if __name__ == '__main__':
    do()

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

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

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

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

print((N//2) * (N - (N//2)))

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

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

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

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

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

Solution (Python):
import math

k = int(input())
print((k // 2) * math.ceil(k / 2))

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

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

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

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

if __name__ == '__main__':
    main()

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

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

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

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

Solution (Python):
n = int(input())
k = (n + 1) // 2
g = n // 2
print(k*g)

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

Solution (Python):
from math import ceil
K = int(input())
print(int(K / 2) * int(ceil(K / 2)))

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

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

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

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

print((a//2)*(a-a//2))

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

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

print(int(cou))

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

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

Solution (Python):
print(int(input()) ** 2 >> 2)

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

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

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

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

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

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

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

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

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

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

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())

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

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

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

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

e = k // 2
o = k - e

print(e * o)

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

e = k // 2
o = k - e

print(e * o)

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

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

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

print(even * odd)

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

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

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

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

evens = K // 2
odds = K - evens

print(evens * odds)

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

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

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

Solution (Python):

import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

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

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

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

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

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

Solution (Python):
from math import ceil

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

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

even = (K//2)
odd = K-(even)

print(odd*even)

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

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

Solution (Python):

import math




K = int(input())

print ( (K - math.floor(K/2)) * (math.floor(K/2)) )

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

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

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

Solution (Python):
from math import ceil
K = int(input())
print(K//2 * ceil(K/2))

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

e = K // 2
o = K - e
print(e*o)

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

Solution (Python):
K=int(input())
if K%2==0:
  K2=K//2
  K1=K2
else:
  K2=(K-1)//2
  K1=(K+1)//2
print(K1*K2)

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

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

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

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

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

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

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

if k%2==0:
  ki=k//2
  gu=k//2
else:
  ki=(k+1)//2
  gu=k//2

ret=ki*gu
  
print(ret)

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

kisu=[]
gusu=[]
for i in range(1,A+1):
  if i % 2:
    kisu.append(i)
  else:
    gusu.append(i)
import itertools
print(len(list(itertools.product(kisu,gusu))))

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

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

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

print(int(ans))

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

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

Solution (Python):

import sys


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



def main():
    K = int(input())
    solve(K)

if __name__ == '__main__':
    main()

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

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

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

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

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

Solution (Python):
import sys
def input():
    return sys.stdin.readline()[:-1]

N = int(input())
if N&1:
    print((N//2)*(N//2+1))
else:
    print((N//2)**2)

Solution (Python):

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

Solution (Python):
from math import ceil
n = int(input())
print(n//2*ceil(n/2))

Solution (Python):
k = int(input())
a = 0 
b = 0 

for i in range(k):
    if (i+1) % 2 == 0:
        a += 1
    else:
        b += 1

print(a*b)

Solution (Python):
k = int(input())
import math
odd = math.floor((k + 1) /2)
even = math.floor(k / 2)
print(odd * even)

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

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

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

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

Solution (Python):

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

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

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

Solution (Python):
import math

n = int(input())

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

Solution (Python):
from sys import stdin
import bisect
from itertools import groupby
 
n = int(stdin.readline().rstrip())

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

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

Solution (Python):




import sys














def main():
    k = int(sys.stdin.readline().rstrip())
    if k % 2 == 0:
        e_c, o_c = k // 2, k // 2
    else:
        e_c, o_c = k // 2, k // 2 + 1

    ans = e_c * o_c
    print(ans)


if __name__ == "__main__":
    
    main()

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

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

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

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

Solution (Python):

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