You would like to write a list of positive integers $1,2,3,\ldots$ using your computer. However, you can press each key $0$ – $9$ at most $n$ times during the process.
What is the last number you can write?
The only input line contains the value of $n$ .
Print the last number you can write.
For sample 1, You can write the numbers $1,2,\ldots,12$ . This requires that you press key $1$ five times, so you cannot write the number $13$ .