При компиляции выскакивают ошибки

#include "Finalexam.h"
#include <iostream>
using namespace std;
struct List_of_Finalexam
{
    Finalexam object;
    List_of_Finalexam *next;
};
#pragma once
 
 
 
class Group_Finalexam //:public ABS_Group
{
    
public:
 
    List_of_Finalexam *begin;
    Group_Finalexam()
    {
        begin = NULL;
    }
    void add_to_begin(Finalexam obj);
    void add_to_end(Finalexam obj);
    void add_by_position(Finalexam obj, int pos);
    void Delete_by_position(int pos);
    void show_list();
    void Finalexam();
 
};
 
 
void Group_Finalexam::add_to_begin(Finalexam obj)
{
 
    List_of_Finalexam *newelem = new List_of_Finalexam;
    newelem->object = obj;
    newelem->next = begin;//  newelem->next = NULL
                          //  while(first != 0) newelem->next = first;
    
    begin = newelem;
 
}
 
void Group_Finalexam::add_to_end(Finalexam obj)
{
    List_of_Finalexam *current;
    current = begin;
    while (current->next != 0)
    {
        current = current->next;
    }
 
    List_of_Finalexam *newelem = new List_of_Finalexam;
    newelem->object = obj;
    newelem->next = NULL;
    current->next = newelem;
}
void Group_Finalexam::add_by_position(Finalexam obj, int pos)
{
    List_of_Finalexam *newelem = new List_of_Finalexam;
 
    newelem->object = obj;
    newelem->next = NULL;
    if (    pos == 1 )// when the list is empty 
    {
        newelem->next = newelem;
        begin = newelem;
        return;
    }
 
    List_of_Finalexam *temp = begin;
    for (int i(0); i<pos-2; i++)
    {
        temp = temp->next;
    }
 
    newelem->next = temp->next;
    temp->next = newelem;
}
void Group_Finalexam::show_list()
{
    if (begin == 0)
    {
        cout << "\n  The list is empty, create new objects please." << endl;
    }
    List_of_Finalexam *current;
    current = begin;
 
    while (current)
    {
        current->object.Show();
        current = current->next;
    }
}
 
 
void Group_Finalexam::Fianlexam()
{
    int Fianlexam;
    cout <<"\n  Enter the number of ships to show the best Shipbuilding companies: "<<endl;
    cout <<"\n  ";cin >> Fianlexam;
    
    if (begin == 0)
    {
        cout << "\n  The list is empty, create new objects please." << endl;
    }
    List_of_Finalexam *temp = begin;    
 
    cout << "\n\n\n  So, the best insuranse companies with over then "<<Fianlexam<<"$ peyments are : \n\n\n";
    while (temp != 0)
    {
        
        if(temp->object.Get_Finalexam() > Fianlexam )
        {
            temp->object.Show();
        }
        temp = temp->next;
    }
 
}
 
void Group_Finalexam::Delete_by_position(int pos)
{
    if (begin == 0)
    {
        cout << "\n  The list is empty, create new objects please." << endl;
        return;
    }
    // deletes node in position pos
    List_of_Finalexam *current = begin;
    
    if ( pos == 1)
    {
        begin = current->next;// first will point to  the second node
        delete current;
        return;
    }
 
 
    for(int i(0); i< pos-2; i++)
    {
        current = current->next;
        // current points to n - 1 node in list
    }
    List_of_Finalexam *newelem = current->next;// nth node
    current->next = newelem->next;// (n+1)nth node  
    delete newelem;
 
}

void Group_Finalexam::add_to_begin(Finalexam obj)
{
   ...

void Group_Finalexam::add_to_begin(::Finalexam obj)
{
   ...