Java Calculator Extended

Multi-functional java calculator.You can count your average, convert euro into any other currency or use casual calculator using basic operations +,-,*,/.Enjoy!

import java.util.*;
import java.io.* ;

class start {
   static String again;
   static float div;
   public static BufferedReader reader;
   public static void main (String args[]) throws IOException {
   reader = new BufferedReader(new InputStreamReader(System.in));

           System.out.println('\n' + "Vlozte (1) pre kalkulacky, (2) pre priemer.");
           String dec1 = reader.readLine();
           int dec2 = Integer.parseInt(dec1);
             if (dec2 == 1) {
             do {
         System.out.println("Vlozte (1) pre numericku kalkulacku, (2) pre euro kalkulacku:");
         String decision = reader.readLine();
         int decision2 = Integer.parseInt(decision);
         if(decision2 == 1) {
         System.out.println('\n' + "Vybrali ste si numericku kalkulacku.");



      System.out.println("Vloz prve cislo:");
      String num1 = reader.readLine();
      float n1 = Float.parseFloat(num1);

        System.out.println("Vyber si operaciu: (+, -, *, /)");
        String op1 = reader.readLine();
        char op2 = op1.charAt(0);

          System.out.println("Vloz druhe cislo:");
          String num2 = reader.readLine();
          float n2 = Float.parseFloat(num2);

           try {
           if (op2 == '+') {
            float plus;
            plus = n1+n2;
            System.out.println('\n'+ "Sucet je: " + plus);
                           } // ends IF statement.
               } // ends try.
      catch(ArithmeticException v) {
            System.out.println("Chyba: " + v.getMessage());
                                   } // ends catch.

           try {
           if (op2 == '-') {
            float minus;
            minus = n1-n2;
            System.out.println('\n'+ "Rozdiel je: " + minus + ".");
                           }
               }
      catch (ArithmeticException v) {
             System.out.println("Chyba: " + v);
                                    }

           try {
           if (op2 == '*') {
            float mult;
            mult = n1*n2;
            System.out.println('\n'+ "Sucin je: " + mult + ".");
                           }
               }
      catch (ArithmeticException v) {
             System.out.println("Chyba: " + v);
                                    }

           try {
           if (op2 == '/' && n2 == 0)
            throw new ArithmeticException ("Delenie nulou.");
           if (op2 == '/' && n2 != 0) {
            div = n1/n2;
            System.out.println('\n'+ "Podiel je: " + div + ".");
                                      } // ends IF statement.
               } // ends try.
       catch (ArithmeticException v) {
             System.out.println("Chyba: " + v.getMessage());
                                    } // ends catch.
         } // ends higher numeric calculation IF statement.



      if (decision2 == 2) {
       System.out.println('\n' + "Vybrali ste si euro kalkulacku.");
       System.out.println("Vlozte pocet eur: ");
       String euro = reader.readLine();
       int euro2 = Integer.parseInt(euro);

           try {
           if (euro2 == 0 || euro2 > 4)
            System.out.println(euro2 + " eur je priblizne " + euro2*30 + " korun.");
           if (euro2 == 1)
            System.out.println(euro2 + " euro je priblizne " + euro2*30 + " korun.");
           if (euro2 == 2 || euro2 == 3 || euro2 == 4)
            System.out.println(euro2 + " eura su priblizne " + euro2*30 + " korun.");
               } // ends try before catch.
      catch (ArithmeticException v) {
             System.out.println("Chyba: " + v);
                                    } // ends catch.
                          } // ends higher euro calculation IF statement.

      System.out.println('\n' + "Opakovat?. a/n");
      again = reader.readLine();
             } // ends do.

      while (!again.equals("n"));
             System.exit(0);
             } // ends higher calculation IF statement.


      do {
      if (dec2 == 2) {
           System.out.println('\n' + "Vybrali ste si priemer znamok.");
       System.out.println("Vyberte si Vas pocet znamok (2-5):");
                     } // ends higher IF statement.
       String pocet1 = reader.readLine();
       int pocet2 = Integer.parseInt(pocet1);

           try {
           if (pocet2 < 6 && pocet2 > 1) {
           if (pocet2 == 5) {
            System.out.println("Vlozte prve cislo:");
            String c1 = reader.readLine();
            float c2 = Float.parseFloat(c1);

             System.out.println("Vlozte druhe cislo:");
             String c3 = reader.readLine();
             float c4 = Float.parseFloat(c3);

              System.out.println("Vlozte tretie cislo:");
              String c5 = reader.readLine();
              float c6 = Float.parseFloat(c5);

               System.out.println("Vlozte stvrte cislo:");
               String c7 = reader.readLine();
               float c8 = Float.parseFloat(c7);

                System.out.println("Vlozte piate cislo:");
                String c9 = reader.readLine();
                float c10 = Float.parseFloat(c9);

      System.out.println("Vas priemer je: " + (c2 + c4 + c6 + c8 + c10)/5);
                            } // ends lower IF statement.

           if (pocet2 == 4) {
                System.out.println("Vlozte prve cislo:");
                String c11 = reader.readLine();
                float c12 = Float.parseFloat(c11);

                 System.out.println("Vlozte druhe cislo:");
                 String c13 = reader.readLine();
                 float c14 = Float.parseFloat(c13);

                  System.out.println("Vlozte tretie cislo:");
                  String c15 = reader.readLine();
                  float c16 = Float.parseFloat(c15);

                   System.out.println("Vlozte stvrte cislo:");
                   String c17 = reader.readLine();
                   float c18 = Float.parseFloat(c17);

          System.out.println("Vas priemer je: " + (c12+c14+c16+c18)/4);
                             } // ends lower IF statement.

               if (pocet2 == 3) {
                System.out.println("Vlozte prve cislo:");
                String c19 = reader.readLine();
                float c20 = Float.parseFloat(c19);

                 System.out.println("Vlozte druhe cislo:");
                 String c21 = reader.readLine();
             float c22 = Float.parseFloat(c21);

              System.out.println("Vlozte tretie cislo:");
              String c23 = reader.readLine();
                  float c24 = Float.parseFloat(c23);

          System.out.println("Vas priemer je: " + (c20 + c22 + c24)/3);
                                } // ends lower IF statement.

           if (pocet2 == 2) {
            System.out.println("Vlozte prve cislo:");
            String c25 = reader.readLine();
            float c26 = Float.parseFloat(c25);

             System.out.println("Vlozte druhe cislo:");
             String c27 = reader.readLine();
             float c28 = Float.parseFloat(c27);

      System.out.println("Vas priemer je: " + (c26 + c28)/2);
                            } // ends lower IF statement.

           System.out.println('\n' + "Opakovat? a/n");
           again = reader.readLine();
               } // ends higher average IF statement.
               } // ends try before catch.
      catch (ArithmeticException v) {
             System.out.println("Chyba: " + v);
               } // ends catch.
               } // ends do.

           while(!again.equals("n"));
                 System.exit(0);
 }
}