diff --git a/lab09/Makefile b/lab09/Makefile
index 08c2234..4701f6a 100644
--- a/lab09/Makefile
+++ b/lab09/Makefile
@@ -3,9 +3,9 @@ CC = gcc
 CFLAGS = -Wall -std=c11
 
 #Input file
-INPUT = input1.txt
+INPUT = input5.txt
 OUTPUT = output.txt
-REF = ref1.txt
+REF = ref5.txt
 # Source file
 SRCS = lab9.c
 # Output
diff --git a/lab09/lab9.c b/lab09/lab9.c
index 522c4e1..5229350 100644
--- a/lab09/lab9.c
+++ b/lab09/lab9.c
@@ -12,16 +12,22 @@
 #define ERROR_CODE 1
 #define OK_CODE 0
 #define MAX_STRING_LEN 256
+#define SCAN_MAX_LEN 255
+#define SCAN_FORMAT_LEN 16
 #define IS_EQUAL 0
 #define INDEX_OFFSET 1
 #define BASE_TEN 10
-#define DOUBLE 2
 
-#define SHORT 1
-#define INTEGER 2
-#define FLOAT 3
-#define CHAR 4
-#define STRING 5
+#define TYPE_SHORT 1
+#define TYPE_INTEGER 2
+#define TYPE_FLOAT 3
+#define TYPE_CHAR 4
+#define TYPE_STRING 5
+
+#define NEWLINE '\n'
+#define VALUE_SEPARATOR ','
+#define NULL_TERMINATOR '\0'
+#define SENTINEL_STRING "E"
 
 char A_NUMBER[] = "A01385066";
 
@@ -36,10 +42,8 @@ void insertNode(NODE **head, void *data)
     NODE *node;
 
     node = malloc(sizeof(NODE));
-
     node->data = data;
     node->next = *head;
-
     *head = node;
 }
 
@@ -51,96 +55,25 @@ void freeList(NODE *head)
     {
         temp = head;
         head = head->next;
-
         free(temp->data);
         free(temp);
     }
 }
 
-NODE* readFile(char *filepath, int *type, int *count)
-{
-    FILE *file;
-    file = fopen(filepath, "r");
-
-    if (file == NULL)
-    {
-        return NULL;
-    }
-
-    if (fscanf(file, "%d", type) != EXPECTED_INPUT)
-    {
-        fclose(file);
-        return NULL;
-    }
-
-    int ch; // skip newlines characters and EOF
-    while ((ch = fgetc(file)) != '\n' && ch != EOF) {}
-
-    char   *format;
-    NODE   *head;
-    size_t size;
-
-    head   = NULL;
-    *count = 0;
-
-    format = *type == SHORT   ? "%hd" :
-             *type == INTEGER ? "%d"  :
-             *type == FLOAT   ? "%f"  :
-             " %c";
-
-    size = *type == SHORT   ? sizeof(short) :
-           *type == INTEGER ? sizeof(int)   :
-           *type == FLOAT   ? sizeof(float) :
-           *type == CHAR    ? sizeof(char)  :
-           MAX_STRING_LEN;
-
-    while (READING)
-    {
-        void *data;
-
-        data = malloc(size);
-
-        if (*type == STRING)
-        {
-            if (fscanf(file, "%255[^,\n]", (char *)data) != EXPECTED_INPUT ||
-                strcmp((char *)data, "E") == IS_EQUAL)
-            {
-                free(data);
-                break;
-            }
-        }
-        else
-        {
-            if (fscanf(file, format, data) != EXPECTED_INPUT ||
-                (*type == CHAR &&
-                *(char *)data == 'E'))
-            {
-                free(data);
-                break;
-            }
-        }
-
-        insertNode(&head, data);
-        (*count)++;
-
-        ch = fgetc(file);
-        if (ch == EOF)
-        {
-            break;
-        }
-        if (ch == '\n')
-        {
-            continue;
-        }
-    }
-
-    fclose(file);
-    return head;
-}
-
 int compare(void *a, void *b, int type)
 {
-    if (type == SHORT || type == INTEGER)
+    if (type == TYPE_SHORT)
+    {
+        short va;
+        short vb;
+
+        va = *(short *)a;
+        vb = *(short *)b;
+
+        return (va > vb) - (va < vb);
+    }
+
+    if (type == TYPE_INTEGER)
     {
         int va;
         int vb;
@@ -151,7 +84,7 @@ int compare(void *a, void *b, int type)
         return (va > vb) - (va < vb);
     }
 
-    if (type == FLOAT)
+    if (type == TYPE_FLOAT)
     {
         float va;
         float vb;
@@ -162,7 +95,7 @@ int compare(void *a, void *b, int type)
         return (va > vb) - (va < vb);
     }
 
-    if (type == CHAR)
+    if (type == TYPE_CHAR)
     {
         char va;
         char vb;
@@ -182,8 +115,8 @@ NODE* split(NODE *head)
     NODE *slow;
     NODE *second;
 
-    slow = head;
     fast = head;
+    slow = head;
 
     while (fast != NULL && fast->next != NULL)
     {
@@ -206,6 +139,7 @@ NODE* merge(NODE *first, NODE *second, int type)
     {
         return second;
     }
+
     if (second == NULL)
     {
         return first;
@@ -216,60 +150,206 @@ NODE* merge(NODE *first, NODE *second, int type)
         first->next = merge(first->next, second, type);
         return first;
     }
-    else
-    {
-        second->next = merge(first, second->next, type);
-        return second;
-    }
+
+    second->next = merge(first, second->next, type);
+    return second;
 }
 
 NODE* mergeSort(NODE *head, int type)
 {
+    NODE *second;
+
     if (head == NULL || head->next == NULL)
     {
         return head;
     }
 
-    NODE *second;
-
     second = split(head);
-    head   = mergeSort(head, type);
+    head = mergeSort(head, type);
     second = mergeSort(second, type);
 
     return merge(head, second, type);
 }
 
+NODE* readFile(char *filepath, int *type, int *count)
+{
+    FILE  *file;
+    NODE  *head;
+    int    ch;
+    size_t size;
+
+    file = fopen(filepath, "r");
+    if (file == NULL)
+    {
+        return NULL;
+    }
+
+    if (fscanf(file, "%d", type) != EXPECTED_INPUT)
+    {
+        fclose(file);
+        return NULL;
+    }
+
+    ch = fgetc(file);
+    while (ch != NEWLINE && ch != EOF)
+    {
+        ch = fgetc(file);
+    }
+
+    head = NULL;
+    *count = 0;
+
+    size = MAX_STRING_LEN;
+    if (*type == TYPE_SHORT)
+    {
+        size = sizeof(short);
+    }
+    else if (*type == TYPE_INTEGER)
+    {
+        size = sizeof(int);
+    }
+    else if (*type == TYPE_FLOAT)
+    {
+        size = sizeof(float);
+    }
+    else if (*type == TYPE_CHAR)
+    {
+        size = sizeof(char);
+    }
+
+    while (READING)
+    {
+        char  buffer[MAX_STRING_LEN];
+        char  scanFormat[SCAN_FORMAT_LEN];
+        void *data;
+        char *end;
+        long  longValue;
+        float floatValue;
+        int   scanResult;
+
+        data = malloc(size);
+        if (data == NULL)
+        {
+            fclose(file);
+            freeList(head);
+            return NULL;
+        }
+
+        scanResult = snprintf(scanFormat, SCAN_FORMAT_LEN, "%%%d[^,\n]", SCAN_MAX_LEN);
+        if (scanResult < 0)
+        {
+            free(data);
+            fclose(file);
+            freeList(head);
+            return NULL;
+        }
+
+        if (fscanf(file, scanFormat, buffer) != EXPECTED_INPUT)
+        {
+            free(data);
+            break;
+        }
+
+        if (strcmp(buffer, SENTINEL_STRING) == IS_EQUAL)
+        {
+            free(data);
+            break;
+        }
+
+        if (*type == TYPE_SHORT)
+        {
+            longValue = strtol(buffer, &end, BASE_TEN);
+            if (*end != NULL_TERMINATOR || longValue < SHRT_MIN || longValue > SHRT_MAX)
+            {
+                free(data);
+                fclose(file);
+                freeList(head);
+                return NULL;
+            }
+            *(short *)data = (short)longValue;
+        }
+        else if (*type == TYPE_INTEGER)
+        {
+            longValue = strtol(buffer, &end, BASE_TEN);
+            if (*end != NULL_TERMINATOR || longValue < INT_MIN || longValue > INT_MAX)
+            {
+                free(data);
+                fclose(file);
+                freeList(head);
+                return NULL;
+            }
+            *(int *)data = (int)longValue;
+        }
+        else if (*type == TYPE_FLOAT)
+        {
+            floatValue = strtof(buffer, &end);
+            if (*end != NULL_TERMINATOR)
+            {
+                free(data);
+                fclose(file);
+                freeList(head);
+                return NULL;
+            }
+            *(float *)data = floatValue;
+        }
+        else if (*type == TYPE_CHAR)
+        {
+            if (strlen(buffer) != INDEX_OFFSET)
+            {
+                free(data);
+                fclose(file);
+                freeList(head);
+                return NULL;
+            }
+            *(char *)data = buffer[0];
+        }
+        else
+        {
+            strncpy((char *)data, buffer, MAX_STRING_LEN);
+            ((char *)data)[MAX_STRING_LEN - INDEX_OFFSET] = NULL_TERMINATOR;
+        }
+
+        insertNode(&head, data);
+        (*count)++;
+
+        ch = fgetc(file);
+        if (ch == EOF)
+        {
+            break;
+        }
+        if (ch == NEWLINE)
+        {
+            continue;
+        }
+    }
+
+    fclose(file);
+    return head;
+}
+
 void printValue(FILE *file, void *data, int type)
 {
-    if (type == SHORT)
+    if (type == TYPE_SHORT)
     {
-        short v;
-        v = *(short *)data;
-        fprintf(file, "%hd", v);
+        fprintf(file, "%hd", *(short *)data);
         return;
     }
 
-    if (type == INTEGER)
+    if (type == TYPE_INTEGER)
     {
-        int v;
-        v = *(int *)data;
-        fprintf(file, "%d", v);
+        fprintf(file, "%d", *(int *)data);
         return;
     }
 
-    if (type == FLOAT)
+    if (type == TYPE_FLOAT)
     {
-        float v;
-        v = *(float *)data;
-        fprintf(file, "%.1f", v);
+        fprintf(file, "%.1f", *(float *)data);
         return;
     }
 
-    if (type == CHAR)
+    if (type == TYPE_CHAR)
     {
-        char v;
-        v = *(char *)data;
-        fprintf(file, "%c", v);
+        fprintf(file, "%c", *(char *)data);
         return;
     }
 
@@ -281,8 +361,12 @@ void writeOutput(char *filepath, NODE *head, int type, int isError)
     FILE *file;
 
     file = fopen(filepath, "w");
+    if (file == NULL)
+    {
+        return;
+    }
 
-    if (isError == 1)
+    if (isError == ERROR_CODE)
     {
         fputs("Error\n", file);
         fclose(file);
@@ -292,31 +376,29 @@ void writeOutput(char *filepath, NODE *head, int type, int isError)
     while (head != NULL)
     {
         printValue(file, head->data, type);
-
         if (head->next != NULL)
         {
-            fputc(',', file);
+            fputc(VALUE_SEPARATOR, file);
         }
-
         head = head->next;
     }
 
-    fputc('\n', file);
+    fputc(NEWLINE, file);
     fclose(file);
 }
 
 int main(int argc, char *argv[])
 {
+    NODE *head;
+    int   type;
+    int   count;
+
     if (argc < EXPECTED_ARGUMENTS)
     {
         printf("Usage: %s <input_file> <output_file>\n", argv[PROGRAM_FILE]);
         return 1;
     }
 
-    NODE *head;
-    int  type;
-    int  count;
-
     head = readFile(argv[INPUT_FILE], &type, &count);
 
     if (head == NULL)
@@ -326,9 +408,7 @@ int main(int argc, char *argv[])
     }
 
     head = mergeSort(head, type);
-
     writeOutput(argv[OUTPUT_FILE], head, type, OK_CODE);
-
     freeList(head);
 
     return 0;
diff --git a/lab09/output.txt b/lab09/output.txt
index 776e6d6..a210e76 100644
--- a/lab09/output.txt
+++ b/lab09/output.txt
@@ -1 +1 @@
-101,158,205,219,317,347,412,501,516,604,629,732,739,813,826,945,32767
+apple,banana,blackberry,blueberry,cherry,grape,kiwi,lemon,mango,orange,peach,pear,pineapple,raspberry,strawberry,watermelon