import java.util.Scanner;

class Base5
{
   /* ---
      atoi(s): Ascii to Integer conversion function in base 5
      --- */
   private static int atoi(String s)
   {
      int startpos, sign;
      int value;
      char next_digit;
      int  value_of_digit;
      int i;

      /* -------
         Convert string to two's compl. representation
         ------- */
      if (s.charAt(0) == '-')
       { sign = -1;
         startpos = 1;
       }
      else
       { sign = 1;
         startpos = 0;
       }

      value = 0;
      for (i = startpos; i < s.length(); i++)
      { 
         next_digit = s.charAt(i);
	 value_of_digit = (int) next_digit - (int) '0';

         value = 5*value + value_of_digit;
      }

      if (sign == -1)
         value = -value;

      return(value);
   }


   public static String itoa(int value)
    {
      int sign, i, j;
      String result;
      char next_char;
      int  next_digit;

      /* -------
         Handle trivial case...
         ------- */
      if (value == 0)
         return("0");

      /* -------
         Check sign
         ------- */
      if (value < 0)
       { sign = -1;
         value = -value;
       }
      else
       { sign = 1;
       }

      /* -------
         Convert number part
         ------- */
      result = "";

      do
       { 
	 next_digit = value % 5;
	 next_char = (char) (next_digit + '0') ;
         result = next_char + result;              // Append at front !!

         value = value / 5;

       } while (value > 0);

      // Put in the negative sign....
      if (sign == -1)
       { 
         result = "(minus)" + result;
       }
      else
       { 
         result = "+" + result;    // optional...
       }


      return(result);
    }


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

      String s1, s2;
      int i1, i2;

      System.out.print("Enter an base 5 integer (string) s1: ");
      s1 = in.next();
      i1 = atoi(s1);    // Same effect as: i1 = Integer.parseInt(s1); !!!!
      System.out.println(s1 + " = " + i1 + " (dec)\n");

      System.out.print("Enter an base 5 integer (string) s2: ");
      s2 = in.next();
      i2 = atoi(s2);    // Same effect as: i2 = Integer.parseInt(s2);
      System.out.println(s2 + " = " + i2 + " (dec)\n");


      System.out.println("sum (in base 5) = " + itoa(i1+i2) );
      System.out.println("product (in base 5) = " + itoa(i1*i2) );
   }
}