static void Main(string[] args)
{
Console.WriteLine("Digite a expressão com 3 variaveis (w, x e z)");
String expression = Console.ReadLine();
Evaluator sentence = new Evaluator(expression);
Dictionary<String,Expression> variables = new Dictionary<String,Expression>();
Console.WriteLine("w=");
variables.Add("w", new Number(Convert.ToInt32(Console.ReadLine())));
Console.WriteLine("x=");
variables.Add("x", new Number(Convert.ToInt32(Console.ReadLine())));
Console.WriteLine("z=");
variables.Add("z", new Number(Convert.ToInt32(Console.ReadLine())));
int result = sentence.Interpret(variables);
Console.WriteLine(result);
Console.ReadKey();
}