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())
m=0
s=0
for i in range(10):
    if n//(10**i)==0:
        m=i-1
        break

for i in range(m):
    s+=9*10**i*(i+1)

s+=(n-10**m+1)*(m+1)

print(s)
