diff --git a/ex-4/dip.c b/ex-4/dip.c
deleted file mode 100644
index 778ea9e..0000000
--- a/ex-4/dip.c
+++ /dev/null
@@ -1,117 +0,0 @@
-#include <math.h>
-#include <stdlib.h>
-#include <string.h>
-#include <gsl/gsl_rng.h>
-
-int main(int argc, char **argv)
-  {
-
-  // Set default options.
-  //
-  size_t N = 50000;          // number of events.
-  size_t n = 50;             // number of bins.
-  double p_max = 10;         // maximum value of momentum module.
-
-  // Process CLI arguments.
-  //
-  for (size_t i = 1; i < argc; i++)
-    {
-         if (!strcmp(argv[i], "-N")) N     = atol(argv[++i]);
-    else if (!strcmp(argv[i], "-n")) n     = atol(argv[++i]);
-    else if (!strcmp(argv[i], "-p")) p_max = atof(argv[++i]);
-    else
-      {
-      fprintf(stderr, "Usage: %s -[hiIntp]\n", argv[0]);
-      fprintf(stderr, "\t-h\tShow this message.\n");
-      fprintf(stderr, "\t-N integer\tThe number of events to generate.\n");
-      fprintf(stderr, "\t-n integer\tThe number of bins of the histogram.\n");
-      fprintf(stderr, "\t-p float\tThe maximum value of momentum.\n");
-      return EXIT_FAILURE;
-      }
-    }
-
-  // Initialize an RNG.
-  //
-  gsl_rng_env_setup();
-  gsl_rng *r = gsl_rng_alloc(gsl_rng_default);
-
-  // Generate the angle θ uniformly distributed on a sphere using the
-  // inverse transform:
-  //
-  //   θ = acos(1 - 2X)
-  //
-  // where X is a random uniform variable in [0,1), and the module p of
-  // the vector:
-  //
-  //   p² = p_v² + p_h²
-  // 
-  // uniformly distributed between 0 and p_max. The two components are
-  // then computed as:
-  //
-  //   p_v = p⋅cos(θ)
-  //   p_h = p⋅sin(θ)
-  //
-  // The histogram will be updated this way.
-  // The j-th bin where p_h goes in is given by:
-  //
-  //   step = p_max / n
-  //   j = floor(p_h / step)
-  //
-  // Thus an histogram was created and a structure containing the number of
-  // entries in each bin and the sum of |p_v| in each of them is created and
-  // filled while generating the events.
-  //
-  struct bin
-    {
-    size_t amo;  // Amount of events in the bin.
-    double sum;  // Sum of |p_v|s of all the events in the bin.
-    };
-  struct bin *histo = calloc(n, sizeof(struct bin));
-
-  // Some useful variables.
-  //
-  double step = p_max / n;
-  struct bin *b;
-  double theta;
-  double p;
-  double p_v;
-  double p_h;
-  size_t j;
-
-  for (size_t i = 0; i < N; i++)
-    {
-    // Generate the event.
-    // 
-    theta = acos(1 - 2*gsl_rng_uniform(r));
-    p = p_max * gsl_rng_uniform(r);
-
-    // Compute the components.
-    //
-    p_v = p * cos(theta);
-    p_h = p * sin(theta);
-
-    // Update the histogram.
-    //
-    j = floor(p_h / step);
-    b = &histo[j];
-    b->amo++;
-    b->sum += fabs(p_v);
-    }
-
-  // Compute the mean value of each bin and print it to stodut
-  // together with other useful things to make the histogram.
-  //
-  printf("bins: \t%ld\n", n);
-  printf("step: \t%.5f\n", step);
-  for (size_t i = 0; i < n; i++)
-    {
-    histo[i].sum = histo[i].sum / histo[i].amo;
-    printf("\n%.5f", histo[i].sum);
-    };
-
-  // free memory
-  gsl_rng_free(r);
-  free(histo);
-
-  return EXIT_SUCCESS;
-  }