PROGRAMMING:Output string at specified location
Write a program, input a string and then input 2 characters, output all characters in the string from the position matching the first character to the position matching the second character.
Example: (instructions in brackets)
###Input example:
```in
program
r
g
```
###Output example:
```out
rog
```
answer：If there is no answer, please comment
Example: (instructions in brackets)
###Input example:
```in
program
r
g
```
###Output example:
```out
rog
```
answer：If there is no answer, please comment