How to reject characters/ letters in a java program

When the program asks the user to input 10 elements (numbers), but the user entered any letter or word, I want the program to display "INVALID INPUT". I tried an if statement but it doesn't work. Any help is much appreciated!

This is my code:

        int [] Array = new int[10];
        int index;

        Scanner input = new Scanner(System.in);

            System.out.println("Enter 10 elements:");

            for (int i = 0; i < 10; i++) {
                Array[i] = input.nextInt();
            }

        System.out.print("Enter an index you want to retrieve: ");
        index = input.nextInt();

        System.out.print("Element at index "+index+" is " + Array[index]);
    }
}

You can use a try-catch and catch a InputMismatchException, where you can then handle it accordingly.

Like so:

    try{
       int [] Array = new int[10];
        int index;
        Scanner input = new Scanner(System.in);
        System.out.println("Enter 10 elements:");
        for (int i = 0; i < 10; i++) {
            Array[i] = input.nextInt();
        }
        System.out.print("Enter an index you want to retrieve: ");
        index = input.nextInt();
        System.out.print("Element at index "+index+" is " + Array[index]);
    }catch(InputMismatchException e){
        System.out.println("INVALID INPUT");
    }

For example, when I input:

spectric is not cool

I get:

INVALID INPUT

Because spectric is cool