Module: (Python) Workshop - 5. Handling strings. "A little about Ancient Rome and Julius Caesar"

Problem

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