#include 
#include 

using namespace std;

int main(){
        
        double firstNumber = 0.0, secondNumber = 0.0, result = 0.0;
        char operation = 'x';        
        
        while (true){
        
                try{
                
                        cout << "Birinci sayi, isaret , ikinci sayi :";
                        cin >> firstNumber >> operation >> secondNumber;
          
                              if(cin.fail())
                        {
                                            {
              cin.clear();
                                              cin.ignore(numeric_limits::max(),'\n');
                                              throw string("Hatali Giris");
                        Giris");
            }
                        
                        switch (operation){
                                case '+':
                                        result = firstNumber + secondNumber;
                                                break;
                                case '-':
                                        result = firstNumber - secondNumber;
                                                break;
                                case '*':
                                        result = firstNumber * secondNumber;
                                                break;
                                case '/':
                                        result = firstNumber / secondNumber;
                                                break;
                                                
                                default:
                                        result = '0';
                                }
                }
                                
                catch(string msg){
                        msg)
        {
          cout << msg << endl;
                  endl;
          continue;
                }
                
                cout << result << endl;
                
                }        
        }