class Square {
    private int x;
    public Square() { }
    public Square(int x) {
	this.x=x;
    }
    public Square(int x, int y) {
	if (x!=y)
	    System.out.println("Error!Using 1st input");
	this.x = x;
    }
    public int getPerim() { return 4*x; }
    // public void getPerim() { } // won't work!
    public void getPerim(String s) { 
	System.out.println(s+getPerim());
    }
}

public class squares {
    public static void main(String[] args) {
	Square s1 = new Square();
	Square s2 = new Square(1);
	Square s3 = new Square(2,1);
	System.out.println(s2.getPerim());
	s3.getPerim("The perimeter is ");
    }
}
/* output:
   Error! Using first input.
   4
   The perimeter is 8
*/