Thread: unable to instantiate derived class!!!

i have made Animal an abstract base class,
iam supposed to be able to create Dog, Cat and Snake objects,
but there is an error.
please help

Code:

#include"stdafx.h"
#include<iostream>
#include<string>
using namespace std;
class Animal
{
	string name;
protected:
	Animal(const string& nameP) :name(nameP){}
public:
	virtual string getSound() = 0;
	string getName() const { return name; }
};
class Dog :public Animal
{
public:
	Dog(const string& nameP) :Animal(nameP){}
	string getSound()const{ return "woof"; }
};
class Cat :public Animal
{
public:
	Cat(const string& nameP) :Animal(nameP){}
	string getSound()const{ return "meow"; }
};
class Snake :public Animal
{
public:
	Snake(const string& nameP) :Animal(nameP){}
	string getSound()const{ return "hiss"; }
};
void report(const Animal& animal);
int main()
{
	Dog rocky("Rocky");
	Cat sylvester("Sylvester");
	Snake eikens("Eikens");
	Animal* array[] = { &rocky, &sylvester, &eikens };
	for (auto x : array)
		report(*x);
}
void report(const Animal& animal)
{
	cout << animal.getName() << " says\t" << animal.getSound() << endl;
}