void matrix (int x, int y, char letter);

void matrix (int x, int y, char letter)
{
      int c = 0;
      while (y > 0)
      {
            while (c < x)
            {
                   cout << letter;
                   c++;
            }
            c = 0;
            cout << "\n";
            y--;
      }
}

/* this is pseudocode */
function print_inner_first (matrix)
   if size(matrix) == 1 X 1 (be mindful of matrices without an exact center here)
      output the center value
      return to caller
   else 
      call print_inner_first (trim_outer_rim(matrix))
   end if

   print 'outer rim' of matrix starting at top center position
end function

//recursive
int gcd(int x, int y)
{
  if (y == 0)
     return x;
  else
     return gcd(y, x % y);
}

//iterative
int gcd(int x, int y)
{
    while (y != 0) {
        int remainder = x % y;
        x = y;
        y = remainder;
    }
    return x;
}