Print vowels with words in Java

I'm a beginner of Java. I'm learning this course and need some help Basically, the user will enter a string and the program will print out vowels on only one line

import java.util.Scanner; 

class Main {
  public static void main(String[] args) {
    Scanner inp = new Scanner(system.in);
    System.out.print("In:");
    String word = inp.nextLine();
    //write your code below
    for(int whatsat = 0; whatsat < word.length(); whatsat++){
      if (word.charAt(whatsat).equals("a")){  //how to declare mutiple letters?
        System.out.print(word.charAt(whatsat));
      }

  }
}
}