static void Main()
 {
     ReversePolishNotation rpn = new ReversePolishNotation();
     List<Tuple<string[], int>> testInputs = new List<Tuple<string[], int>>();
     testInputs.Add(Tuple.Create(new string[] {"2", "1", "+", "3", "*"}, 9));
     testInputs.Add(Tuple.Create(new string[] {"4", "13", "5", "/", "+"}, 6));
     foreach (var input in testInputs)
     {
         if (rpn.Solve(input.Item1) != input.Item2)
         {
             WriteLine("Tests failed for {0}!", input.Item2);
             return;
         }
     }
     WriteLine("Tests passed!");
 }