diff --git a/du4/program.c b/du4/program.c
index f2acd33..eaecf7a 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -12,47 +12,69 @@ struct student {
 struct student databaza[SIZE];
 int size = 0;
 
-int find_student(const char* name) {
-    for (int i = 0; i < size; i++) {
-        if (strcmp(databaza[i].name, name) == 0) {
+int find_student(const char* name){
+    for (int i = 0; i < size; i++){
+        if (strcmp(databaza[i].name, name) == 0){
             return i;
         }
     }
     return -1;
 }
+int compare(const void* a, const void* b) {
+    struct student* s1 = (struct student*)a;
+    struct student* s2 = (struct student*)b;
+
+    if (s1->votes > s2->votes) {
+        return -1;
+    } else if (s1->votes < s2->votes) {
+        return 1;
+    } else {
+        return strcmp(s1->name, s2->name);
+    }
+}
 
 int main() {
     char line[SIZE];
     memset(databaza, 0, sizeof(databaza));
-
     while (fgets(line, SIZE, stdin)) {
         char* end = NULL;
         int votes = strtol(line, &end, 10);
 
-        if (votes <= 0) {
+        if (votes <= 0 || *end != ' '){
+            printf("Chyba: Nespravny format vstupu!\n");
             continue;
         }
 
         char name[SIZE];
         memset(name, 0, SIZE);
         strncpy(name, end + 1, strlen(end + 1) - 1);
-
         int id = find_student(name);
+        if (id < 0){
+            if (size >= SIZE){
+                printf("Chyba: Databaza je plna!\n");
+                continue;
+            }
 
-        if (id < 0) {
             strncpy(databaza[size].name, name, SIZE - 1);
             databaza[size].votes = votes;
             size++;
-        } else {
+        }
+        else
+        {
             databaza[id].votes += votes;
         }
     }
 
+    if (size == 0){
+        printf("Chyba: Nebol nacitany ziadny platny zaznam!\n");
+        return 1;
+    }
+
+    qsort(databaza, size, sizeof(struct student), compare);
+
     printf("Vysledky:\n");
     for (int i = 0; i < size; i++) {
         printf("%d %s\n", databaza[i].votes, databaza[i].name);
     }
-
     return 0;
 }
-