Day 2 - char vs. int

When I think about it the value of a can be little higher then 100 and less then -100.
Should I change char in to short int or int.
Let it be int.

Now it looks like this:

 class MyClass
  {
   public:
    MyClass( int P_a ): M_a( P_a ){}

	void clac() { std::cout << "Do not disturb! calc in progress ..." << std::endl; }

   private:
    int a;
  };

Fortunately I didn't change too much. Just char became int.