Preheat oven to 350°. Cook shells according to package directions. In a large bowl combine soup and water. Prepare stuffing and then combine with chicken and Miracle Whip. Pour about 2 cans worth of the soup mixture on the bottom of a 9 x 13 inch pan. Stuff the shells with the stuffing/chicken. Layer shells in the pan. Pour remaining soup mixture over the shells. Cover with foil and bake for 45 minutes. Sprinkle with cheese and bake 15 minutes longer.