void porownaj(struct lista **head, struct lista **headA){

    if((*head)!=NULL && (*headA)!=NULL){

        struct lista *walker1=(*head);
        struct lista *walker2=(*headA);

        while(walker1->next!=NULL){
            while(walker2->next!=NULL){
                if(walker1->key==walker2->key){
                    int x=walker1->key;
                    add_head_por(&headB,x);
                    walker2=walker2->next;

                }
                walker2=walker2->next;

            }
            walker1=walker1->next;
        }


    }


}