Thread: g++ giving me BIG troubles!!!

I wrote this program and it compiles fine with Visual Studio. Problem is my teacher wants it compiled with g++ and I cant get it to compile. It says, "Main must return 'int'" Heres the entire program. I would appreciate any help/suggestions anyone can provide.

Code:

// '***' Represents start of new 'sub-function' 

//   <<Got rid of header files and conio>>
#include <iomanip>
#include <iostream>



using std::cout;
using std::cin;
using std::setw;


//max int of 15.
const unsigned x = 15;


//define matrix as x+1 by x+1.
typedef unsigned MatrixType[x+1][x+1];


//declare y as user defined dimension size (odd numbers only)
unsigned   Y;

MatrixType Matrix;


//"sub-function" definitions.
void Description();
void Dimensions();
void Generate();
void Print();
void Exit();


//MAIN FUNCTION--include "sub-functions" in main function.
void main()
{
	    	
	Description();
	Dimensions();
	Generate(); 
	Print();
	Exit();
	}



//***Information screen using cout statements.
void Description()
{
	cout<<"????????????????????????????????????????????????????????????????????????????\n";
	cout<<"?                                                                          ?\n";
	cout<<"?                       MAGIC SQUARE PROGRAM                               ?\n";
	cout<<"?                                                                          ?\n";
	cout<<"?                                                                          ?\n";
	cout<<"?      This is a program that creates a magic square that                  ?\n";
	cout<<"?      will be filled in by you. A magic square is an x by x matrix        ?\n";
	cout<<"?      that is filled with numbers so that the rows, columns and           ?\n";
	cout<<"?      diagnol lines add up to be the same number.                         ?\n";	
	cout<<"?                                                                          ?\n";
	cout<<"?                                                                          ?\n";
	cout<<"????????????????????????????????????????????????????????????????????????????\n";
	cout<<"\n";
	cout<<"\n";
	cout<<"\n";
	cout<<"\n";
}


//***function for getting the dimensions from keyboard.
void Dimensions()
{
	cout<<"Get ready to make your Magic Square!\n";   
	cout<<"Please enter an ODD number (3 through 15).\n";
	cout<<"After that hit Enter.\n\n\n\n";
	cin>>  Y;
}


	

//***function for generating magic square with user defined input.
void Generate()
{

    
	unsigned i;
	unsigned Dsquare;
	unsigned Row;
	unsigned Column;
	
	//arrange matrix so that Magic Square will work.
	Row = 1;                
	Column = (Y+1)/2;
	Matrix[Row][Column] = 1;   
	Dsquare = Y*Y;
	
	for (i=2; i<=Dsquare; i++)
	{
		if ((i-1)%Y==0)
			Row++;
		else
		{
			Row--;   
			Column++;
		
			if (Row==0)
				Row = Y;
		
			else if (Column==(Y+1))
				Column = 1;
		}
		Matrix[Row][Column] = i;
	}
}


//***function for printing results.
void Print()
{

	
	unsigned Row;
	unsigned Column;
	
	//creating lined box around numbers.
	cout<<"\n\n\n\n\n\n\n\n"<<setw((4*Y-10)/2)
		<<""<<setw(2)
		<<Y<<" x "
		<<setw(2)<<Y<<" Square\n";
	
	cout<<"ÚÄ";
	
	//Creates top of box (margin spacing).
	for (Column=1; Column<=Y; Column++)
		cout<<"ÄÄÄÄ";
	    cout<<"¿\n";
	
	for (Row=1; Row<=Y; Row++)
	{
		//Creates 'sides' of box.
		cout<<"³ ";
		
		for (Column=1; Column<=Y; Column++)
			cout<<setw(3)<<Matrix[Row][Column]<<" ";
		    cout<<"³\n";
	}
	cout<<"ÀÄ";
	
    //Creates bottom of box (margin spacing).
	for (Column=1; Column<=Y; Column++)
		cout<<"ÄÄÄÄ";
 	    cout<<"Ù\n";
}


//***function for exit screen.
void Exit()
{
	cout<<"This is a Magic Square!!!\n";
	cout<<"\nThank you for using this program...\n";
	cout<<"Please press any key to exit!\n\n\n\n";
}