def main():
  from sys import stdin
  input=stdin.readline
  n = int(input())
  d = 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991
  tmp = str(d * n)
  delta = len(tmp) - len(str(d))
  if delta == 0:
    ans = '0.' + tmp
  else:
    ans = tmp[:delta] + '.' + tmp[delta:]
  print(ans)
main()