PROGRAMMING:Statistics
Please count the number of times the number 2 appears in all integers of a given range [l, R].
For example, given the range [2, 22], the number 2 appears once in the number 2, once in the number 12, once in the number 20, once in the number 21, twice in the number 22, so the number 2 appears six times in the range.
###Input format:
Input a total of 1 line, two positive integers L and R (1 ≤ L ≤ R ≤ 10000), separated by a space.
###Output format:
Output a total of 1 line, indicating the number of times the number 2 appears.
###Input example:
```in
2 22
```
###Output example:
```out
six
```
answer：If there is no answer, please comment
For example, given the range [2, 22], the number 2 appears once in the number 2, once in the number 12, once in the number 20, once in the number 21, twice in the number 22, so the number 2 appears six times in the range.
###Input format:
Input a total of 1 line, two positive integers L and R (1 ≤ L ≤ R ≤ 10000), separated by a space.
###Output format:
Output a total of 1 line, indicating the number of times the number 2 appears.
###Input example:
```in
2 22
```
###Output example:
```out
six
```
answer：If there is no answer, please comment