diff --git a/Assignment_3/lib/Stack.cpp b/Assignment_3/lib/Stack.cpp
index 5f5a9f5..8774ec6 100644
--- a/Assignment_3/lib/Stack.cpp
+++ b/Assignment_3/lib/Stack.cpp
@@ -10,9 +10,9 @@ Stack::Stack(ADTOperationQueue * queue){
     op_queue = queue;
 }
 
-bool Stack::push(int element) { return false; }
-bool Stack::pop(int element) { return false; }
-bool Stack::size(int element) { return false; }
+void Stack::push(int element) { return; }
+int Stack::pop() { return 0; }
+void Stack::size() { return 0; }
 
 std::string Stack::print_stack(){
     Node* c = this->first->next;
diff --git a/Assignment_3/lib/Stack.h b/Assignment_3/lib/Stack.h
index d4b9a68..d4bc6ea 100644
--- a/Assignment_3/lib/Stack.h
+++ b/Assignment_3/lib/Stack.h
@@ -9,8 +9,8 @@ class Stack {
         Stack(ADTOperationQueue * queue);
         Node* first;
     public:
-        bool push(int element);
-        bool pop(int element);
-        bool size(int element);
+        void push(int element);
+        int pop();
+        int size();
         std::string print_stack();
 };
\ No newline at end of file