Java calculator

In Slovak Language.

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

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

       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();
      int n1 = Integer.parseInt(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();
            int n2 = Integer.parseInt(num2);


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

}
}
      catch (ArithmeticException v) {
             System.out.println("Chyba: " + v.getMessage());
}
}
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.");
}
catch (ArithmeticException v) {
  System.out.println("Chyba: " + v);
}
}
   System.out.println('\n' + "Spustit znova? y/n");
   again = reader.readLine();
}

   while(!again.equals("n"));
}
}