C++ Calculator

#include <iostream>
#include <stdlib.h>
using namespace std;
// Variables
char line[] = "----------------------\n";
char subline[] = "---";
int num1, num2;
char op;
int main()
{
  // HEADER
  cout << line;
  cout << subline << " C++ Calculator " << subline << "\n";
  cout << line;
  system("sleep 2");
  cout << "Enter a Number: \n";
  cin >> num1;
  cout << "Enter another Number: \n";
  cin >> num2;
  cout << "Choose an operator via the list below.\n";
  // Operators
  cout << "1. +\n";
  cout << "2. -\n";
  cout << "3. *\n";
  cout << "4. /\n";
  cin >> op;
  // Math
  if(op == '+')
  {
   cout << num1 << "+" << num2 << "=" << num1+num2 << "\n";
  } else if(op == '-') {
   cout << num1 << "-" << num2 << "=" << num1-num2 << "\n";
  } else if(op == '*') {
   cout << num1 << "*" << num2 << "=" << num1*num2 << "\n";
  } else if (op == '/') {
    while(num2 == 0)
    {
      cout << "Enter a NON-Zero Divisor:\n";
      cin >> num2;
    }
   cout << num1 << "/" << num2 << "=" << num1/num2 << "\n";
  } else {
    cout << "No Such Operator Exists";
  }
}