import java.io.*;

import java.net.*;

import java.util.*;

class PTB2_TCP_Server

{

public static void main(String arg[])throws Exception

{

ServerSocket sksv=new ServerSocket(6789);

while(true)

{

Socket socketconnect=sksv.accept();

DataInputStream hieu=new DataInputStream(socketconnect.getInputStream());

Double a=hieu.readDouble();

System.out.print("a: "+a);

Double b=hieu.readDouble();

System.out.print("b: "+b);

Double c=hieu.readDouble();

System.out.print("c: "+c);

String ketqua=ptb2(a,b,c);

DataOutputStream gui=new DataOutputStream(socketconnect.getOutputStream());

gui.writeUTF(ketqua);

System.out.print("Da gui ket qua "+ketqua);

}

}

public static String ptb2(double a,double b,double c)

{

double delta=b*b-4*a*c;

if(delta<0)

return "ptvn";

else

if(delta==0)

{

double x=(double)-b/(2*a);

return "pt co 2 nghiem x1=x2="+x;

}

else

{

double x1=(-b-Math.sqrt(delta))/(2*a);

double x2=(-b+Math.sqrt(delta))/(2*a);

return "pt co 2 nghiem pb x1="+x1+";x2="+x2;

}

}

}