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.
n=int(input())
a=[0,9,99,999,9999,99999,999999,9999999,99999999,999999999,9999999999]
x=1
ans=0
for i in range(1,11):
    if n>=a[i]:
        ans+=((a[i]-a[i-1])*x)
    else:
        ans+=((n-a[i-1])*(x))
        break
    x+=1
print(ans)