C++ error:unresolved external symbol _main referenced in function "int_cdecl invoke_main(void)"

#include "stdafx.h"
#include <iostream>
#include "myqueue.h"
using namespace std;
template <class T>
int main()
{
	myqueue <int> intQueue;
	cout <<"size ="<< intQueue.size() << endl;
	intQueue.add(10);
	intQueue.add(20);
	intQueue.add(30);
	cout << intQueue.retrieve() << endl;
	intQueue.remove();
	intQueue.add(40);
	intQueue.add(50);
	cout << intQueue.retrieve() << endl;
	intQueue.remove();
	intQueue.add(60);
	cout <<"size ="<< intQueue.size() << endl;
	while
		(!intQueue.isEmpty())
	{
		cout << intQueue.retrieve() << endl;
		intQueue.remove();
	}
	cout <<"size ="<< intQueue.size() << endl;
	return 0;
   
}

#include<stack>
using namespace std;
template <class T>
class myqueue
{
private:stack <T> st1, st2;
public:
	myqueue();
	~myqueue();
	bool add(T element);
	T retrieve();
	bool remove();
	bool isEmpty();
	int size();
};

#include "stdafx.h"
#include "myqueue.h"
#include <stack>
using namespace std; 

template <class T>
myqueue<T>::myqueue()
{
}
template <class T>
myqueue<T>::~myqueue()
{
}
template <class T>
bool myqueue<T>::add(T element) {
	st1.push(element);
	return true;
}
template <class T>
bool myqueue<T>::isEmpty() {
	if (st1.size()== 0) {
		cout << "Empty queue" << endl;
		return true;
	}
	cout << "Not empty queue" << endl;
	return false;
}
template <class T>
int myqueue<T>::size() {
	return st1.size();
}
template <class T>
T myqueue<T>::retrieve() {
	while (!st1.empty) {
		st2.push(st1.top);
		st1.pop();
	}
	T item = st2.top();
	while (!st2.empty) {
		st1.push(st2.top());
		st2.pop();
	}
	return item;
}
template <class T>
bool myqueue<T>::remove() {
	if (!st1.empty) {
		while (!st1.empty) {
			st2.push(st1.top);
			st1.pop();
		}

		while (!st2.empty) {
			st1.push(st2.top());
			st2.pop();
		}
		return true;
	}
	else return false;
}