def fact(n)
  return 1 if n == 0
  return n * fact(n - 1)
end

def comb(n, k)
  return fact(n) / fact(n - k) / fact(k)
end

def perm(n, k)
  return fact(n) / fact(n - k)
end

n = gets.to_i

if n <= 4
  puts 0
else
  puts 12.0 * comb(99, 5) * comb(99 - 5, n - 5) / comb(99, n) * perm(99 - 5, 25 - 5) / perm(99, 25) * fact(5)
end