SimpleCalc V.3

// SimpleCalc.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <windows.h>
#include <iostream>
#include <cstdlib>
using namespace std;

//Variables
int fnum;
int snum;
int result;
char sym;
char st();
char loop = 'y';
char ff();
int calc();
int wait;

//Main stuff

int main(int nNumberofArgs, char*
		  pszArgs[])

{
	SetConsoleTitle( TEXT( "SimpleCalc" ) );

cout << ("Welcome to SimpleCalc!") <<endl;
cout << ("Project By: Christopher Altig!") <<endl;


while (loop == 'y')
{
ff();
if (sym == '*')
{
	result = fnum * snum;
	cout << "Answer:" << result <<endl;
	st();
}
else if (sym == '/')
{
	result = fnum / snum;
	cout << "Answer:" << result <<endl;
	st();
}
else if (sym == '-')
{
	result = fnum - snum;
	cout << "Answer:" << result <<endl;
	st();
}
else if (sym == '+')
{
	result = fnum + snum;
	cout << "Answer:" << result <<endl;
	st();
}
else if (sym == '%')
{
	result = snum % fnum;
	cout << "Answer:" << result <<endl;
	st();
}
}
return 0;
}
//Down here V V V
char st()
{
	cout << ("Do another calculation (Y/N): ");
	cin >> loop;
if (loop == 'n')
	{
		exit (EXIT_SUCCESS);
	}
else if (loop !='n' && loop !='y')
{
	cout << ("Error: Invalid Character!") <<endl;
	st();
}

return 0;
}

char ff()
{
cout << "Symbol here:"; cin >> sym;
if (sym == '*' || sym == '/' || sym == '+' || sym == '-' || sym == '%')
	{
	calc();
	}
else
{
	cout << ("Error: Invalid Character!") <<endl;
	ff();
}

return 0;
}

int calc()
{
	snum = 0;
	fnum = 0;
	system("CLS");
	cout << "Number 1:"; cin >> fnum;
	cout << "Number 2:"; cin >> snum;
		if (snum >= 0 || fnum >= 0)
		{
		cout << ("Error: Invalid Number!") << endl;
		wait = 0;
			while (wait <= 5)
			{
		wait++;
			}
			system("CLS");
			calc();
		}
		else
		{
			ff();
		}
return 0;
}
//Up there ^ ^ ^