初学Java 求最大公约数

 import java.util.Scanner;
 public class GreatesCommonDivisor {
   public static void main(String[] args) {
       Scanner input = new Scanner(System.in);

       System.out.print("Enter first integer: ");
       int n1 = input.nextInt();
       System.out.print("Enter second integer: ");
       int n2 = input.nextInt();

       int gcd = ;
       int k = ;
       while (k <= n1 && k <= n2) {
           if (n1 % k ==  && n2 % k == )
               gcd = k;
           k++;
       }

       System.out.println("The greatest common divisor for " + n1 + " and " + n2 + " is " + gcd);
   }
 }