diff --git a/du4/Makefile b/du4/Makefile
new file mode 100644
index 0000000..3c2c463
--- /dev/null
+++ b/du4/Makefile
@@ -0,0 +1,13 @@
+CFLAGS= -std=c99 -g -Wall
+
+all: train
+
+%.o: %.c
+	gcc -c -o $@ $< $(CFLAGS)
+
+train: main.o a_train.o
+	gcc main.o a_train.o -o train 
+
+clean:
+	rm *.o train
+
diff --git a/du4/a_train.c b/du4/a_train.c
new file mode 100644
index 0000000..2d85ee4
--- /dev/null
+++ b/du4/a_train.c
@@ -0,0 +1,64 @@
+#include "a_train.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+struct car* add_car(struct car* first,const char* target) {
+  	struct car* newcar = calloc(1,sizeof(struct car));
+	if(!newcar) return first;
+
+	strcpy(newcar->value, target);
+	newcar->next = NULL;
+
+	if(first == NULL){
+		return newcar;
+	}
+	struct car* temp = first;
+	while(temp->next !=NULL){
+		temp = temp->next;
+	}
+	temp->next = newcar;
+      	return first;
+}
+
+void print_train(struct car* first) {
+	struct car* temp = first;
+	while(temp != NULL) {
+		printf("%s\n",temp->value);
+		temp = temp->next;
+	}
+}
+
+void cancel_train(struct car* first) {
+	struct car* temp;
+	while(first != NULL){
+		temp = first -> next;
+		free(first);
+		first = temp;
+	}
+}
+
+
+struct car* clear_train(struct car* first, const char* target) {
+	struct car* temp = first;
+	struct car* prev = NULL;
+
+	while(temp != NULL){
+		if(strcmp(temp->value, target)== 0){
+		if(prev == NULL){
+			first= temp->next;
+			free(temp);
+			temp= first;
+
+		}else{
+			prev->next= temp->next;
+			free(temp);
+			temp = prev->next;
+		}
+	}else{
+		prev= temp;
+		temp =temp->next;	
+	}
+	}
+	return first;
+}
+
diff --git a/du4/a_train.h b/du4/a_train.h
new file mode 100644
index 0000000..5982bfe
--- /dev/null
+++ b/du4/a_train.h
@@ -0,0 +1,51 @@
+#ifndef TRAIN_H
+#define TRAIN_H
+#define SIZE 100
+
+/**
+ * Jeden vozen vlaku
+ */
+struct car {
+    /**
+     * Nazov cielovej  stanice
+     */
+    char value[SIZE];
+    /**
+     * Smenik na dalsi vozen
+     */
+    struct car* next;
+};
+
+/**
+ * Prida vozen na koniec vlaku.
+ *
+ * @arg nazov cielovej stanice, ktory sa ma priradit novemu voznu.
+ * @return smernik na zaciatok vlaku.
+ */
+struct car* add_car(struct car* first,const char* target);
+
+
+/**
+ * Vypise vsetky vozne vo vlaku
+ *
+ * @arg smernik na prvy vozen
+ */
+void print_train(struct car* first);
+
+/**
+ * Zrusenie vsetkych voznov vo vlaku.
+ * @arg smernik na prvy vozen
+ */
+void cancel_train(struct car* first);
+
+/**
+ * Vyradenie vsetkych voznov, ktorych cielova stanica je target
+ *
+ * @arg smernik na prvy vozen
+ * @arg cielova stanica, ktora sa ma vyradit z vlaku.
+ * @return smernik na novy prvy vozen
+ *
+ */
+struct car* clear_train(struct car* first,const char* target);
+
+#endif // TRAIN_H
diff --git a/du4/a_train.o b/du4/a_train.o
new file mode 100644
index 0000000..695b375
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diff --git a/du4/main.c b/du4/main.c
new file mode 100644
index 0000000..d64f05a
--- /dev/null
+++ b/du4/main.c
@@ -0,0 +1,17 @@
+#include "a_train.h"
+#include <stdio.h>
+
+// Testovaci subor pre vlak
+int main(){
+    struct car* train = NULL;
+    train = add_car(train,"Presov");
+    train = add_car(train,"Bratislava");
+    train = add_car(train,"Levoca");
+    train = add_car(train,"Spiska Nova Ves");
+    print_train(train);
+    clear_train(train,"Levoca");
+    print_train(train);
+    cancel_train(train);
+
+    return 0;
+}
diff --git a/du4/main.o b/du4/main.o
new file mode 100644
index 0000000..35751c3
Binary files /dev/null and b/du4/main.o differ
diff --git a/du4/program.c b/du4/program.c
deleted file mode 100644
index 79062c0..0000000
--- a/du4/program.c
+++ /dev/null
@@ -1,73 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-
-#define MAX 101
-
-// funkcia, ktorá vracia zodpovedajúcu zatváraciu zátvorku
-char expected_close(char open) {
-    switch (open) {
-        case '(': return ')';
-        case '{': return '}';
-        case '[': return ']';
-        case '<': return '>';
-        default: return 0;
-    }
-}
-
-int main(void) {
-    char line[MAX];
-    char stack[MAX];
-    int pos[MAX]; // pozície otvorených zátvoriek
-    int top = -1; // index vrcholu zásobníka
-
-    // načítanie jedného riadku
-    if (fgets(line, MAX, stdin) == NULL)
-        return 0;
-
-    // odstrániť znak nového riadku, ak je prítomný
-    line[strcspn(line, "\n")] = '\0';
-
-    printf("Read: %s\n", line);
-
-    int ok = 1;
-    int length = strlen(line);
-
-    for (int i = 0; i < length; i++) {
-        char ch = line[i];
-
-        // ak je otváracia zátvorka
-        if (ch == '(' || ch == '{' || ch == '[' || ch == '<') {
-            top++;
-            stack[top] = ch;
-            pos[top] = i + 1; // indexovanie od 1
-        }
-        // ak je zatváracia zátvorka
-        else if (ch == ')' || ch == '}' || ch == ']' || ch == '>') {
-            if (top < 0) {
-                printf("Unexpected closing bracket %c in %d\n", ch, i + 1);
-                ok = 0;
-                break;
-            }
-
-            char last_open = stack[top];
-            char expected = expected_close(last_open);
-            if (ch != expected) {
-                printf("Crossed bracket %c in %d, expected %c\n", ch, i + 1, expected);
-                ok = 0;
-                break;
-            }
-            top--;
-        }
-    }
-
-    if (ok && top >= 0) {
-        printf("Missing closing bracket for %c from %d\n", stack[top], pos[top]);
-        ok = 0;
-    }
-
-    if (ok)
-        printf("All brackets OK\n");
-
-    return 0;
-}
-
diff --git a/du4/train b/du4/train
new file mode 100755
index 0000000..b8109a9
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