diff --git a/src/seam-carving.cpp b/src/seam-carving.cpp
index f893bef..0b22704 100644
--- a/src/seam-carving.cpp
+++ b/src/seam-carving.cpp
@@ -12,10 +12,11 @@
 #include <SimpleProgressBar.hpp>
 #include <stb_image_write.h>
 
-// Global flag to silent verbose messages
-bool silent;
-bool test_energy;
+// Global flags
+bool silent = false;
+bool test_energy = false;
 bool energy_recompute_all = false;
+int max_step = 1;
 
 // Get index for any table indexed by [width*(i : height) + (j : width)], but a
 // : dim_long, b : dim_large
@@ -81,7 +82,7 @@ std::vector<float> energy_e1(std::vector<unsigned char> source, int width,
 }
 
 std::vector<int> optimal_seam(std::vector<float> energy, int width, int height,
-                              bool vertical, int max_step = 1) {
+                              bool vertical) {
   /** Given the energy value, returns the optimal seam */
 
   // dyn_energy is indexed by [dim_large*(i : dim_long) + (j : dim_large)]
@@ -195,11 +196,11 @@ std::vector<int> carving_step(const std::vector<unsigned char> source_img,
                               std::vector<unsigned char> &output_img,
                               std::vector<float> &output_energy, int width,
                               int height, int nbChannels, int nbColorChannels,
-                              bool vertical, int max_step=1) {
+                              bool vertical) {
   /** Carves an image and its energy by one seam, and recomputes the energy.
       Returns the optimal seam used */
   std::vector<int> opt_seam =
-    optimal_seam(source_energy, width, height, vertical,max_step=max_step);
+    optimal_seam(source_energy, width, height, vertical);
   remove_seam(source_img, output_img, width, height, nbChannels, vertical,
               opt_seam);
 
@@ -241,8 +242,7 @@ std::vector<int> carving_step(const std::vector<unsigned char> source_img,
 }
 
 void seam_carving(unsigned char *source, int width, int height, int nbChannels,
-                  const char *out_filename, int nbSeams, bool vertical,
-                  bool test_energy = false, int max_step = 1) {
+                  const char *out_filename, int nbSeams, bool vertical) {
   int nbColorChannels = nbChannels > 3 ? 3 : nbChannels;
   int curWidth = width;
   int curHeight = height;
@@ -282,7 +282,7 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
 
     float max_energy = __FLT_MIN__;
     for (auto k = 0; k < width * height; k++) {
-      max_energy = fmax(max_energy, ini_energy[k]);
+      max_energy = std::max(max_energy, ini_energy[k]);
     }
     if (max_energy != 0) {
       for (auto k = 0; k < width * height; k++) {
@@ -307,7 +307,7 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
   for (auto seam_index = 0; seam_index < nbSeams; seam_index++) {
     std::vector<int> opt_seam = carving_step(
         source_img, source_energy, output_img, output_energy, curWidth,
-        curHeight, nbChannels, nbColorChannels, vertical, max_step=max_step);
+        curHeight, nbChannels, nbColorChannels, vertical);
     std::copy(output_img.begin(), output_img.end(), source_img.begin());
     std::copy(output_energy.begin(), output_energy.end(),
               source_energy.begin());
@@ -348,22 +348,26 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
 int main(int argc, char **argv) {
   CLI::App app{"seam-carving"};
   std::string sourceImage;
+  std::string maskImage = "mask.png";
+  std::string outputImage = "output.png";
+  int nbSeams = 1;
+  bool vertical = false;
+  
   app.add_option("-s,--source", sourceImage, "Source image")
       ->required()
       ->check(CLI::ExistingFile);
-  ;
-  std::string outputImage = "output.png";
   app.add_option("-o,--output", outputImage, "Output image")->required();
-  int nbSeams = 1;
-  app.add_option("-n,--nb-seams", nbSeams, "Number of seams");
-  int max_step = 1;
-  app.add_option("--max-step", max_step, "Max width of step to find a seam");
-  bool vertical = false;
+  app.add_option("-m,--mask", maskImage, "Source image")
+      ->check(CLI::ExistingFile);
+
+  app.add_option("-n,--nb-seams", nbSeams, "Number of seams")
+      ->check(CLI::Number);
+  app.add_option("--max-step", max_step, "Max width of step to find a seam")
+      ->check(CLI::Number);
+
   app.add_flag("--vertical", vertical,
                "Vertical carving (remove vertical seams)");
-  silent = false;
   app.add_flag("--silent", silent, "No verbose messages");
-  test_energy = false;
   app.add_flag("--test-energy", test_energy,
                "Don't resize image, just try the specified energy function");
   app.add_flag("--energy-recompute-all", energy_recompute_all,
@@ -376,8 +380,8 @@ int main(int argc, char **argv) {
       stbi_load(sourceImage.c_str(), &width, &height, &nbChannels, 0);
   nbSeams = std::min(nbSeams, width);
 
-  seam_carving(source, width, height, nbChannels, outputImage.c_str(), nbSeams,
-               vertical, test_energy = test_energy, max_step = max_step);
+  seam_carving(source, width, height, nbChannels, outputImage.c_str(),
+                nbSeams, vertical);
 
   stbi_image_free(source);
   exit(0);