C++ Hesap Makinesi Yapma

#include <iostream>
#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <locale.h>


main () {
baslangic:

    
    char cavab,Yalnis;
    
int a,b,c,d,y;
using namespace std;

 

cout << "\n                            Akilli Hesab Aparati    ";
cout << "\n                       Editor :  by Nmx Thetics \n";
cout << "\n Etmek istediyiniz emeliyyati secin. \n";
cout << "\n   Topalama     [1] \n" << "\n   Cixma        [2] \n" << "\n   Vurma        [3] \n" << "\n   Bolme        [4] \n";
cout << "\nSeciminiz ";
cin >> c;


cout << "\nBirinci reqemi secin = ";
cin >> a;
cout << " Ikinci reqemi secin = ";
cin >> b;

//Toplama//
 if ( c==1 )
 d = ( a+b ); 
//Cixma//
 if ( c==2 )
 d = ( a-b );
//Vurma// 
 if ( c==3 )
 d = ( a*b );
//Bolme// 
 if ( c==4 )
 d = ( a/b );
 
 if ( c>4 )
 d = ( Yalnis);
 
 cout << "\nEmeliyyat ugurla basa catdi " << "\n Hesablamanin neticesi = " << d;
 
 if ( c>4 )
 
 
 cout<<"\nSehv emeliyyat secdiniz.\nXaish edirik [1] ile [4] arasinda bir reqem secin";
 
 cavab=y;
 cout <<"\nDavam etmek ucun [Y] ";
 cin >> cavab;
 
 
 if (cavab= 'y')
goto baslangic;

getch ();
return 0;

}