Problem L. Long-term activity ≡

Statement

On the board, a natural number is written. Timofey wants to maximize this number, meaning he wants all nines to be at the beginning, followed by eights, and so on. In one operation, he can swap any two adjacent digits of the number. Determine the minimum number of operations he needs to achieve this goal.

Input format

A single line of input contains a natural number n.

Output format

Output a single non-negative integer, the answer to the problem.

Constraints

1 ≤ n ≤ 10¹⁰⁰⁰⁰⁰.

Example explanation

Initial string: 2023.

1) 2032.

2) 2302.

3) 3202.

4) 3220.

Sample tests

2023

4