Students who attended schools in ancient Rome solved various problems in the classroom. Here is one of the tasks:
101=1
8181515=4
1111112=0
8888888=14
1010101=3
7000007=?
Let the first number be x and the corresponding n.
Write a program that, given the number x, determines n.
Input
The only non-negative x number not greater than 101001.
Imprint
Output n.
Examples