PROGRAMMING:six hundred and sixty-six
Chinese people like the number 6 very much, because people always like to say 66 Dashun. Math maniac Li likes to digitize everything, so she also defines the word "smooth" as an order of magnitude, 6 for level 1 smooth, 66 for Level 2 smooth, 666 for Level 3 smooth, and so on. You see, the world of math maniacs is always incomprehensible. Today, Li decided to carry on the mathematics to the end, now she set the top n level smoothly and is SN.
```
Sn = 6 + 66 + 666 +... + 66.. 66 (n 6).
```
Suppose you already know the number n, then, can you help Li find Sn?
###Input format:
Enter a positive integer n in the range of [0,10].
###Output format:
Output the value of Sn.
###Input example:
```in
two
```
###Output example:
```out
seventy-two
```
answer：If there is no answer, please comment
```
Sn = 6 + 66 + 666 +... + 66.. 66 (n 6).
```
Suppose you already know the number n, then, can you help Li find Sn?
###Input format:
Enter a positive integer n in the range of [0,10].
###Output format:
Output the value of Sn.
###Input example:
```in
two
```
###Output example:
```out
seventy-two
```
answer：If there is no answer, please comment