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())
if n<10:
    print(n)
elif n<100:
    print(9+(n-9)*2)
elif n<1000:
    print(9+90*2+(n-99)*3)
elif n<10000:
    print(9+90*2+900*3+(n-999)*4)
elif n<100000:
    print(9+90*2+900*3+9000*4+(n-9999)*5)
elif n<1000000:
    print(9+90*2+900*3+9000*4+90000*5+(n-99999)*6)
elif n<10000000:
    print(9+90*2+900*3+9000*4+90000*5+900000*6+(n-999999)*7)
elif n<100000000:
    print(9+90*2+900*3+9000*4+90000*5+900000*6+9000000*7+(n-9999999)*8)
elif n<1000000000:
    print(9+90*2+900*3+9000*4+90000*5+900000*6+9000000*7+90000000*8+(n-99999999)*9)
else:
    print(9+90*2+900*3+9000*4+90000*5+900000*6+9000000*7+90000000*8+900000000*9+10)