Вычисление суммы, разности, произведения и частного чисел, введенных пользователе

#include <iostream>
using namespace std;
 
int main() {
int choise;
double a,b;
cout<<"Please enter the first number: ";
cin>>a;
cout<<"Please enter the second number: ";
cin>>b;
cout<<"Select operation with numbers:"<<endl;
cout<<"1. Calculate the sum."<<endl;
cout<<"2. Calculate the difference."<<endl;
cout<<"3. Calculate the multiplication."<<endl;
cout<<"4. Calculate the division."<<endl;
switch (choise) 
  {
     case 1: 
     {
     cout << a << " + " << b << " = " << a + b << endl;
     break;
     }
     case 2:
     {
     cout << a << " - " << b << " = " << a - b << endl;
     break;
     }
     case 3:
     {
     cout << a << " * " << b << " = " << a * b << endl;
     break;
     }
     case 4:
     {
     cout << a << " / " << b << " = " << a / b << endl;
     break;
     }
     default: cout << "Fuck!!!! Please enter the number..." << endl;
  }
return 0;
}

case 4:
     {
     if (b ==0) 
        cout << "На ноль длить не умею";
     else 
        cout << a << " / " << b << " = " << a / b << endl;
     break;
     }