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.
def f(x):
    t=0
    while x:
        t+=1
        x//=10
    return t
n=int(input())
k=f(n)
digit=0
for i in range(k-1):
    digit+=9*10**(i)*(i+1)
digit+=(n-10**(k-1)+1)*k
print(digit)
