import java.util.Scanner;

class Atof
{
   /* ---
      parseFloat(s): Ascii to float conversion function
      --- */
   public static float myParseFloat(String s)
   {
      float value;          // Return value 
      int   k, sign, pos;

      /* -------
         Check for negative sign
         ------- */
      if (s.charAt(0) == '-')
      { sign = -1;
        pos = 1;           // Start at digit s.charAt(1)
      }
      else
      { sign = 1;
        pos = 0;           // Start at digit s.charAt(0)
      }

      /* ------------------------------------------
         Convert the whole number part first
         ------------------------------------------ */
      value = 0;
      for (k = pos; k < s.length(); k++)
      { 
	 /* ====================================
            Stop when you see a decimal point
            ==================================== */
         if ( s.charAt(k) == '.' )
         {
            pos = k+1;
            break;
         }

         value = (float) (10*value + ( s.charAt(k) - 48 )); 
      }

      /* ------------------------------------------
         Convert the fractional part next
         ------------------------------------------ */
      if ( k < s.length() )
      {
         float f = 10.0f;

         for (k = pos; k < s.length(); k++)
         {
            value = (float) (value + ( s.charAt(k) - 48 )/f);  
            f = f * 10.0f;
         }
      }


      /* ========================================================
         Negate 2's complement representation if first character
	 of input was '-'
	 ========================================================= */
      if (sign == -1)
         value = -value;  // Compute the negative value (flip bits and add 1 !!)

      return(value);      // Return a BINARY 2's compl code 
   }

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

      String s1, s2;
      float f1, f2;

      System.out.print("Enter an float (string) s1: ");
      s1 = in.next();
      System.out.println("We read the numeric string: \"" + s1 + "\"");

      f1 = myParseFloat(s1);  // 

      System.out.println("The float VALUE for this numeric string is: " + f1);


      System.out.print("\nEnter another float (string) s2: ");
      s2 = in.next();
      System.out.println("We read the numeric string: \"" + s2 + "\"");

      f2 = myParseFloat(s2);  // 

      System.out.println("The float VALUE for this numeric string is: " + f2);

      System.out.println("===================================================");
      System.out.println("The sum of the integer values = " + (f1+f2) );
   }
}