On a $50 \times 50$ chessboard, we put, in the lower left corner, a die whose faces are numbered from $1$ to $6$. By convention, the sum of digits on two opposite side of the die equals $7$. Adama wants to move the die to the diagonally opposite corner using the following rule: at each step, Adama can roll the die only on to its right side, or to its top side. We suppose that whenever the die lands on a square, the number on its bottom face is printed on the square. By the end of these operations, Adama wants to find the sum of the $99$ numbers appearing on the chessboard. What are the maximum and minimum possible values of this sum?