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<sup class="upper-index">9</sup>) — the number of books in the library.
import math
def main():
    n = int(input())
    x = int(math.log10(n))
    output = 0
    for i in range(x):
        output += (i+1)*9*(10**i)
    output += (n-10**x+1)*(x+1)
    print(output)
        
main()
        
