PROGRAMMING:Enter the name of the file, open the file and output the contents of the file to the screen.

Write a program, when the user input file name does not exist, you can re-enter, until you enter a correct file name, open the file and output the contents of the file to the screen.
###Input format:
Enter a valid file name.
###Output format:
Output opens the file and displays its contents to the screen.
###Input example:
```in
Please enter the file path and file name: d://1.txt
```
###Output example:
```out
Please enter the file path and file name: d://1.txt
You have successfully opened a file
```






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