diff --git a/du3/program.c b/du3/program.c
new file mode 100644
index 0000000..443ce9c
--- /dev/null
+++ b/du3/program.c
@@ -0,0 +1,29 @@
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define STACK_SIZE 10
+
+struct stack {
+   float values[STACK_SIZE];
+   int size;
+};
+
+void push_stack(float value, struck stack *s){
+   if (s->size >=STACK_SIZE){
+      printf("Zapsinik je plny\n")
+      exit (1);
+}
+s->values[s->size] = value;
+s->size++;
+}
+
+float pop_stack(struct stack *s) {
+   if (s->size <= 0){
+      printf("zasobnik je prazdny \n");
+      exit(1);
+   }
+   s->size--;
+   return s->values[s->size];
+}
+
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..9191c43
--- /dev/null
+++ b/du4/a_train.c
@@ -0,0 +1,18 @@
+#include "a_train.h"
+#include <stdio.h>
+
+struct car* add_car(struct car* first,const char* target) {
+    return NULL;
+}
+dddddddd
+void print_train(struct car* first) {
+}
+
+void cancel_train(struct car* first) {
+}
+
+
+struct car* clear_train(struct car* first, const char* target) {
+	return NULL;
+}
+
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/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;
+}