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 sys
import math
input=sys.stdin.readline
#for _ in range(int(input())):
n=int(input())
i=1
x=0
while(n>0):
    if(n>=9):
        x+=9*i
    else:
        x+=n*i
    n-=9
    i+=1
print(x)