/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Point A1 = new Point(0,3);
		Point A2 = new Point(2,0);
		Point B = new Point(0,0);
 
		System.out.println(
			B.distance(A1,A2)
		);
	}
}
 
class Point {
	double x,y;
 
	Point(double x, double y){
		this.x= x;
		this.y= y;
	}
 
	public double distance(Point A1, Point A2){
		double numerator = Math.abs((A2.y - A1.y)*this.x + (A2.x - A1.x)*this.y + A2.x*A1.y - A2.y*A1.x);
		double denominator = Math.sqrt(Math.pow(A2.y - A1.y,2) + Math.pow(A2.x - A1.x,2));
 
		return numerator/denominator;		
	}
 
}

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