__author__ = 'Zlobober'

n = int(raw_input())
ans = 0
for l in range(1, 11):
    if (l == len(str(n))):
        ans += (n - 10**(l-1) + 1) * l
    elif (l < len(str(n))):
        ans += (9 * 10**(l - 1)) * l
    else:
        break

print ans