#include <iostream>
using namespace std;

class my_matrix {
    int matrix[2][2];
  public:
    void set_entries ();
    int trace () ;
    int determinant();

};

void my_matrix::set_entries () 
 {
 //declaring the entries of the 2 dimensional array.
 for (int i = 0 ; i < 2 ; ++i )
	for (int j = 0 ; j < 2 ;++j)
		matrix[i][j] = i+j ;
 }

int my_matrix::trace() 
 {
 int return_value = 0 ;
 for (int i = 0 ; i < 2 ; ++ i)
	return_value +=matrix[i][i] ;
 
 return return_value ;
 }

int main () {

  my_matrix mat ;
  mat.set_entries ();
  cout << "trace of the matrix " << mat.trace() << endl;
 
return 0; 
}