A9908. Vanya and Books

Vanya got an important task — he should enumerate books in the library and label each book with its number. Each of the $n$ books should be assigned with a number from $1$ to $n$ . Naturally, distinct books should be assigned distinct numbers.

Vanya wants to know how many digits he will have to write down as he labels the books.

The first line contains integer $n$ ( $1<=n<=10^{9}$ ) — the number of books in the library.

Print the number of digits needed to number all the books.

Note to the first test. The books get numbers $1,2,3,4,5,6,7,8,9,10,11,12,13$ , which totals to $17$ digits.

Note to the second sample. The books get numbers $1,2,3,4$ , which totals to 4 digits.