Room Number

Interview

Time limit2sMemory limit128 MB

Summary

Given a room number, count how many plastic digit sets (0-9 each) are needed, treating 6 and 9 as interchangeable when flipped.

Level: Easy2 of 10
Topics: Math, Implementation
Solved: No attempts yet

Problem

Dasom wants to put her room number on the door of her new home using plastic digits.

Plastic digits are sold in sets. Each set contains exactly one digit from 0 through 9. Given the room number N, find the minimum number of digit sets needed to make the number.

The digit 6 can be turned upside down and used as 9, and the digit 9 can be turned upside down and used as 6.

Input

The first line contains the room number N. N is a natural number between 1 and 1,000,000, inclusive.

Output

Print the minimum number of digit sets needed.

Examples4

Example 1
Input
```
9999
```
Expected output
```
2
```
Example 2
Input
```
122
```
Expected output
```
2
```
Example 3
Input
```
12635
```
Expected output
```
1
```
Example 4
Input
```
888888
```
Expected output
```
6
```