diff --git a/work/week6/series/homework2/src/main.cc b/work/week6/series/homework2/src/main.cc
index 1f69766..5ef1abe 100644
--- a/work/week6/series/homework2/src/main.cc
+++ b/work/week6/series/homework2/src/main.cc
@@ -1,28 +1,42 @@
-#include <iostream>
-#include "arithmetic.hh"
-
-#include "pi.hh"
-
 #include <cstdlib>
 #include <cmath>
 #include <iostream>
 #include <iomanip>
+#include <memory>
+
+#include "arithmetic.hh"
+#include "pi.hh"
+#include "series.hh"
+
 /* -------------------------------------------------------------------------- */
 
 int main(int argc, char ** argv) {
 
-    // Parse number of iterations
-    unsigned int N = 10;
+    // Parse method type
+    std::string method = "ar";  // default value
     if (argc > 1) {
-        N = atoi(argv[1]);
+        method = argv[1];
     }
 
-    // Instanciate series object and compute series
-    ComputeArithmetic ar;
-    std::cout << "ComputeArithmetic(" << N << ") = " << ar.compute(N) << std::endl;
+    // Parse number of iterations
+    unsigned int N = 10;  // default value
+    if (argc > 2) {
+        N = atoi(argv[2]);
+    }
+
+    // Instanciate appropriate series object
+    std::string method_label;
+    std::unique_ptr<Series> series; // doesn't point to anything yet
+    if (method == "ar") {
+        series.reset(new ComputeArithmetic);
+        method_label = "ComputeArithmetic";
+    } else if (method == "pi") {
+        series.reset(new ComputePi);
+        method_label = "ComputePi";
+    }
 
-    ComputePi pi;    
-    std::cout << "ComputePi(" << N << ") = " << pi.compute(N) << std::endl;
+    // Compute series
+    std::cout << method_label << "(" << N << ") = " << series->compute(N) << std::endl;
 
     return EXIT_SUCCESS;
 }