import java.util.HashMap;

public class Variables
{
  HashMap<String, Double> dict;

  public Variables()
  {
    dict = new HashMap<String, Double>();
  }

  public void setValue(String s, double val)
  {
    dict.put(s, val);
  }

  public double getValue(String s)
  {
    Double retval = dict.get(s);
    if(retval == null)
    {
      throw new MalformedExpressionException("Variable " + s + " is not defined");
    }
    return (double)retval;
  }

  public String toString()
  {
    return dict.toString();
  }
}