Heat oven to 425 degrees. Prepare pastry. Mix sugar and flour in large bowl. Stir in cherries. Turn into pastry-lined pie plate. Dot with margarine. Cover with top crust that has slits cut in it; seal and flute. Cover edge with 2to 3-inch strip of aluminum foil to prevent excessive browning. Remove foil during last 15 minutes of baking. Bake 35 to 45 minutes or until crust is brown and juice begins to bubble through slits in crust. 8 SERVINGS; 505 CALORIES PER SERVING.