include <iostream>
#include <math.h>
#include <conio.h>
using namespace std;
int main(){
    double n1,n2;
    int inp;
    cout << "Enter number :\n\n\n";
    cout << "_____________________\n\n\n";
    cout << "\tNumber 1 :\n";
    cin >> n1;
    cout << "\t\tNumber 2 :\n";
    cin >> n2;
       if(!cin){
             cout << "\n\t- Error! -\n";
             cin.clear();
             cin.ignore();
             getch();
             return -1;
             }
             cout << "Enter [1] for  [+]\n";
             cout << "Enter [2] for  [-]\n";
             cout << "Enter [3] for  [/]\n";
             cout << "Enter [4] for[*]\n\n\n";
             cout << "___________________\n\n";
             cin >> inp;
           
              switch(inp)
             
             {
                         case 1:
                              cout << "____________________\n";
                              cout << " Summa :\n";
                              cout << "\n\n" << n1+n2 << "\n\n\t";
                              
                              getch();
                              break;
                              case 2:
                                   cout << "____________________\n";
                                   cout << " Summa :\n";
                                   cout << "\n\n" << n1-n2 << "\n\n\t";
                                   getch();
                                   break;
                                   case 3:
                                        cout << "____________________\n";
                                        cout << " Summa :\n";
                                        cout << "\n\n" << n1/n2 << "\n\n\t";
                                        getch();
                                        break;
                                        case 4:
                                             cout << "____________________\n";
                                             cout << " Summa :\n";
                                             cout << "\n\n" << n1*n2 << "\n\n\t";
                                             getch();
                                             break;
                                           
                                                       
                                                     default:
                                                             cout << "\tonly numbers 1 2 3 4\t\n";
                                                             }
                                                             return 0;
                                                             }