First, prepare the simple syrup: Heat ½ cup sugar and ½ cup water until the sugar is dissolved. There is no need to boil. This yields 1 cup of simple syrup. Next, peel and puree 5-6 ataulfo mangos (this should yield about 4 cups of puree). Combine the 4 cups of mango puree with an equal amount of water and ½ cup of the prepared simple syrup. Adjust the amount of simple syrup to your desired sweetness.