Caculator?

    #include "stdafx.h"
    #include <iostream>
    #include <string>

    using namespace std;

int main()
{
       float a;
       float b;
	   float s;
       string choice;
       string cont;

	cout << "Ready to do some math?\nAdd\nSubtract\nMultiply\nDivide\n";
	cin >> choice;
	if (choice == "add")
	{
		cout << "You have Picked add.\n";
		 	{
				cout << "Type in First Number: \n";
				cin >> a;
				cout << "Type in Second Number: \n";
				cin >> b;
				cout << "\n";
				cout << "	" << a <<" + " << b <<" = " <<a+b <<endl;
				cout << "\n";
				cout << "Would you like to continue?\nYes = y\nNo = n\n";
					cin >> cont;
					if (cont == "y")
					{
						main ();
					}
					else (cont == "n");
					{
						return 0;
					}
			}


	}
if (choice == "subtract")
	{
		cout << "You have Picked Subtract.\n";
		 	{
				cout << "Type in First Number: \n";
				cin >> a;
				cout << "Type in Second Number: \n";
				cin >> b;
				cout << "\n";
				cout << "	" << a <<" - " << b <<" = " <<a-b <<endl;
				cout << "\n";
				cout << "Would you like to continue?\nYes = y\nNo = n\n";
					cin >> cont;
					if (cont == "y")
					{
						main ();
					}
					else (cont == "n");
					{
						return 0;
					}
			}


	}
if (choice == "multiply")
	{
		cout << "You have Picked Multiply.\n";
		 	{
				cout << "Type in First Number: \n";
				cin >> a;
				cout << "Type in Second Number: \n";
				cin >> b;
				cout << "\n";
				cout << "	" << a <<" * " << b <<" = " <<a*b <<endl;
				cout << "\n";
				cout << "Would you like to continue?\nYes = y\nNo = n\n";
					cin >> cont;
					if (cont == "y")
					{
						main ();
					}
					else (cont == "n");
					{
						return 0;
					}
			}


	}
if (choice == "divide")
	{
		cout << "You have Picked Divide.\n";
		 	{
				cout << "Type in First Number: \n";
				cin >> a;
				cout << "Type in Second Number: \n";
				cin >> b;
				cout << "\n";
				cout << "	" << a <<" / " << b <<" = " <<a/b <<endl;
				cout << "\n";
				cout << "Would you like to continue?\nYes = y\nNo = n\n";
					cin >> cont;
					if (cont == "y")
					{
						main ();
					}
					else (cont == "n");
					{
						return 0;
					}
			}


	}



char f;
cin >> f;
return 0;
}