Java programminh

a-Write a while loop that ensures the user enters a positive integer number (named amount). Prior to the loop, is the code below. Write the loop below it.

int amount;

System.out.print (Enter a positive integer: );

amount = scan.nextInt ();

b. Write a for loop to print the multiples of 3 from 300 down to 3 (i.e., 300, 297, 294, etc.), each value on a different line (next line down).