import java.io.*;
public class FreezeBoil2
{
  public static void main(String[]args) throws Throwable
  {
    BufferedReader br;
    String Element;
    String line;
    br=new BufferedReader(new InputStreamReader(System.in));
    double FREEZE_PT;
    double BOIL_PT;
    double avgTemp;
    
    System.out.println();
    System.out.print("Enter Element:");
    Element=br.readLine();

    System.out.print("Enter FREEZE_PT:");
    line=br.readLine();
    FREEZE_PT=Double.parseDouble(line);
    if(FREEZE_PT <= 0){    
    System.out.println("Error: Only positive non-zero integers");
    }

    System.out.print("Enter BOIL_PT:");
    line=br.readLine();
    BOIL_PT=Double.parseDouble(line);
    if(BOIL_PT <= 0){
    System.out.println("Error: Only positive non-zero integers");
    }
    
    System.out.print(Element + " freezes at " + FREEZE_PT);
    System.out.println(" and boils at " + BOIL_PT + " degrees.");

    avgTemp=FREEZE_PT+BOIL_PT;
    avgTemp=avgTemp/2.0;
    System.out.println("Halfway between is "+avgTemp+" degrees.");
  }
}

System.out.print("Enter BOIL_PT:");
line=br.readLine();
BOIL_PT=Double.parseDouble(line);
while(BOIL_PT <= 0){
    System.out.println("Error: Only positive non-zero integers");
   System.out.print("Enter BOIL_PT:");
   line=br.readLine();
   BOIL_PT=Double.parseDouble(line);
}