Java help for converting temperature

So if anyone can help. I am not sure what’s wrong. I think I need a while statement.

It keeps giving me an error in the else statement:

import java.util.*; // For class Scanner

public class Tempconversion
{
    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);

        double F = 0;
        double C = 0;
        int ConvertFer = 0;
        int ConvertCel = 1;
        int Done = 3;
        System.out.println("Welcome to the Temperature Converter!\n" +
                           "Enter 0 to convert F --> C and 1 to convert from C --> F.\n" +
                           "Enter 3 when done");

        if (ConvertFer == 0)
            System.out.println("Welcome to the F --> C Converter\n" +
                               "Enter Values to convert: ");
            C = reader.nextDouble();
            F = ((F - 32)*5)/9;
            System.out.println(F + "F = " + C + "C.");

        else
            System.out.println("Welcome to the C --> Fconverter\n" +
                               "Enter Values to convert: ");

            F = reader.nextdouble();
            C = ((C * 90)/5)) + 32;
            System.out.println(C + "C = " + F + "F.");
    }

}

public static void main(String[] args) {
    Scanner reader = new Scanner(System.in);

    double tF = 0.0001;
    double tC = 0.0001;          
    int convertFer = 0;
    int convertCel = 1;

    System.out.println("Welcome to the Temperature Converter!\n"
            + "Enter 0 to convert F --> C and 1 to convert from C --> F.\n"
            + "Enter Control-Z when done!");

    convertFer = reader.nextInt();

    if (convertFer == 0) {
        System.out.println("Welcome to the F --> C Converter!\n" + "Enter Values to convert:");
        while (reader.hasNext()){ 

        tC = reader.nextDouble();

        tF = ((tC - 32) * 5) / 9;
           System.out.println(tC +" F = " + tF + " C");}

     } else {
        System.out.println("Welcome to the C --> F Converter!\n" + "Enter Values to convert:");
        while (reader.hasNext()){

        tF = reader.nextDouble();

        tC = ((tF * 9) / 5) + 32;
           System.out.println(tF + "C = " + tC + " F");}

        System.out.println("Goodbye!");
        System.exit(0);     
     }     
 }