Place pitted cherries in medium saucepan. Stir in water. Bring to boil, stirring occasionally; cover. Simmer on medium-low heat 15 min., stirring occasionally. Place prepared cherries in jelly bag; hang and let drip into bowl until dripping stops. Press bag gently to remove any remaining juices. Measure exactly 3 cups prepared juice into large saucepan. Add sugar; mix well.