from math import floor
def z(n):
  r = 0
  for i in range(1,1000):
    r += 1/pow(i, n)
  return r

x = int(input())
if x >= 21:
  print(0)
  exit()
ans = 0
for i in range(x, x+200):
  ans += z(i)-1
print(floor(ans*1000000))