PLEASE ALWAYS USE CODE TAGS (the <> formatting button) when posting code.
It makes it easier to read your code and also easier to respond to your post.
Hint: You can edit your post, highlight your code and press the <> formatting button.
You can use the preview button at the bottom to see how it looks.
Your program deals with three numbers, but what would, you do if the requirements changed and asked you to handle 100 numbers. Three or 100 numbers the concept for dealing with either should be the same.
You need to rethink your program. I can see using for loops, if/else statements, vector and maybe a switch/case in the program. You could even put parts of the code in functions.
There are several possibilities of what to do all limited by what you know and/or what you are allowed to use.
Break the program into smaller pieces.
1. You might explain what is needed from the user.
2 Get the needed input.
3. Sort the numbers if needed.
4 Print in the correct order.
While thinking about these smaller pieces this could give you an idea of how to store the numbers.
Hope that helps,