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]*13
for i in range(13):
    a[i] = (10**i)-1
for i in range(2,13):
    j=1
    while(j<i):
        a[i] = a[i]- a[j]
        j+=1
count = 0
for i in range(1,13):
    if(n-a[i]>0):
        count += a[i]*i
        n -= a[i]
    else:
        count += n*i
        break
print(count)