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≤109) − the number of books in the library.
Print the number of digits needed to number all the books.
13
17
4
4
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.