I am trying to disallow the user from entering a non-sense answer, however, whenever i input a nonsense answer as shown above, it keeps letting me enter another input. I want the program to display an error message and stop. I don't want it to keep letting the user input until it is not nonsense. Please help me out. Everything else works fine in the code, it is just this requirement that im struggling with. Try to not rewrite the code entirely pls.

Please input a square matrix: jfgiewogn Please input a square matrix