diff --git a/Start_Windows/stack.c b/Start_Windows/stack.c
index e3a90d4..6383694 100644
--- a/Start_Windows/stack.c
+++ b/Start_Windows/stack.c
@@ -10,7 +10,7 @@
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data)
 {
-
+    
 }
 
 // Deletes the top element of the stack (latest added element) and releases its memory. (Pointer to data has to be
diff --git a/Start_Windows/stack.h b/Start_Windows/stack.h
index f7d542d..45714c3 100644
--- a/Start_Windows/stack.h
+++ b/Start_Windows/stack.h
@@ -1,13 +1,19 @@
 #ifndef STACK_H
 #define STACK_H
 
+#define MAX_STACK_SIZE 100
 /* A stack is a special type of queue which uses the LIFO (last in, first out) principle. 
 This means that with each new element all other elements are pushed deeper into the stack. 
 The latest element is taken from the stack. */
 
 #include <stdlib.h>
 
+
 //TODO: passenden Datentyp als struct anlegen
+typedef struct{
+    int items[MAX_STACK_SIZE];
+    int top;
+}StackNode;
 
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data);