import java.util.StringTokenizer;
public class calculator
{
	public static void main(String[] Args)
	{
		String input = "";
		int result;
		for (int i = 0; i < Args.length; i++)
		{
//			System.out.println("Got a chunk: \""+Args[i]+"\"\n");
			input = input+Args[i];
		}
		System.out.println("Here's what I saw: \""+input+"\"");
		float ans = parse(input);
		System.out.println("That equals "+ans+"\n");
		
	}
	public static float parse(String input)
	{
		StringTokenizer Tokenizer = new StringTokenizer(input,"()+-x/",true);
		mathNode tree = parseRec(Tokenizer, false);
		float value = 0;
		try
		{
			value = tree.eval();
		} catch (NullPointerException e)
		{
			System.out.println("That input is not accepted.");
			System.exit(0);
		}
		return value;
	}
	public static mathNode parseRec(StringTokenizer Tokenizer, boolean paren)
	{
		mathNode tree = null;
		mathNode pointer = tree;
		mathNode parent = null;
		while (Tokenizer.hasMoreTokens())
		{
			String chunk = Tokenizer.nextToken();
//			chunk.replaceAll("~","-");
//			System.out.println("Got a symbol: \""+chunk+"\"");			
			if (chunk.equals("("))
			{
				pointer = parseRec(Tokenizer, true);
				pointer.parent = parent;
				if (parent.left == null)
					parent.left = pointer;
				else
					parent.right = pointer;
				pointer = parent.right;
			}
			else if (chunk.equals(")"))
			{
//				System.out.println(tree.left.op+":"+tree.op+":"+tree.right.op);
				return tree;
			}
			else if (chunk.equals("x") || chunk.equals("/"))
			{
				mathNode node = new mathNode(chunk);
				tree = pointer.insertUp(node, tree);
				pointer = node.right;
//				System.out.println(node.op+":"+node.left.op+" Treetop="+tree.op);
				parent = node;
			}
			else if (chunk.equals("+") || chunk.equals("-"))
			{
				mathNode node = new mathNode(chunk);
				node.left = tree;
				node.left.parent = node;
				tree = node;
				pointer = node.right;
				parent = node;
			}
			else
			{
//				System.out.println("Got a character: \""+chunk+"\"");
				mathNode node = new mathNode(chunk);
				pointer = node;
				if (parent != null)
					parent.right = node;
				pointer.parent = parent;
				if (parent != null)
					pointer = parent.right;
				if (tree == null)
					tree = node;
//				System.out.println("Terminal: "+pointer.op+" Treetop:"+tree.op);
			}
		if (tree == null) {System.out.println("WTF Mate!");}
		}
		return tree;
	}
}