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 solve(a):
    ans=0
    tmp=9
    b=1
    while a>0:
        c=min(a,tmp)
        ans+=c*b
        a-=c
        tmp*=10
        b+=1
    return ans

a=int(input())
print(solve(a))
