public int process()
	{
		Stack<Character> stack=new Stack<Character>();
		InputReader in=new InputReader(getClass().getResourceAsStream("/balexp.txt"));
		String line=in.readLine();
		
		for(int i=0;i<line.length();i++)
		{
			char ch=line.charAt(i);
			switch(ch)
			{
					case '(':
					case '[':
					case '{':stack.push(ch);
							 break;
					case  ']':
					case  '}':	
					case  ')':if(!stack.isEmpty())
							{
								char top=stack.pop();
								if(!doesMatch(top,ch))
									return -1;
								break;
							}
							else
							{
								return -1;
							}
					default:break;
							   	
						
			}
		}
		return 0;
	}