Digit 8

Time limit2sMemory limit512 MB

Summary

Given L and R up to 2*10^9, find the minimum number of times digit 8 appears in any integer within [L, R].

Level: Medium5 of 10
Topics: Math, Greedy, String
Solved: No attempts yet

Problem

Two natural numbers L and R are given. Among all natural numbers greater than or equal to L and less than or equal to R, choose a number that contains the digit 8 as few times as possible. Find how many times the digit 8 appears in such a number.

Input

The first line contains L and R. L is a natural number not greater than 2,000,000,000. R is greater than or equal to L and is also not greater than 2,000,000,000.

Output

Print the minimum possible number of digit 8s among all natural numbers from L to R, inclusive.

Examples4

Example 1
Input
```
1 10
```
Expected output
```
0
```
Example 2
Input
```
88 88
```
Expected output
```
2
```
Example 3
Input
```
800 899
```
Expected output
```
1
```
Example 4
Input
```
8808 8880
```
Expected output
```
2
```