You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Shannon and her family use up a lot of strawberry and blueberry jelly , since they eat toast every morning . At the moment , they have a combined total of 6310 grams of jelly . If they have 4518 grams of blueberry jelly , how many grams of strawberry jelly do they have ?
1792