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 = []
r = 0
z = 0
for i in range(1,n+1):
    a.append(i)
    if a[i-1] > 10:
        for k in range(10,n,10):
            if a[i-1] % k >= 1:
                r += len(str(k))
    elif a[i-1] <= 11:
        z += len(str(a[i-1]))
print(z+r)