import math
n = int(input())
if(n%2==0):
  print(int(math.pow(int(n/2),2)))
else:
  print(int(n/2) * int((n+1)/2))

662d2af800b90e3333b3d6ab30317787c9fa942c
<mask token>

<mask token>
if n % 2 == 0:
    print(int(math.pow(int(n / 2), 2)))
else:
    print(int(n / 2) * int((n + 1) / 2))

<mask token>
n = int(input())
if n % 2 == 0:
    print(int(math.pow(int(n / 2), 2)))
else:
    print(int(n / 2) * int((n + 1) / 2))

import math
n = int(input())
if n % 2 == 0:
    print(int(math.pow(int(n / 2), 2)))
else:
    print(int(n / 2) * int((n + 1) / 2))

import math
n = int(input())
if(n%2==0):
  print(int(math.pow(int(n/2),2)))
else:
  print(int(n/2) * int((n+1)/2))
