Please reason step by step, and put your final answer within \boxed{}.
Julia played tag with 4 kids on Wednesday. On Monday, she had played with 6 kids and on Tuesday, she had played with 17 kids. She continued playing with kids for the rest of the week: 12 kids on Thursday, 10 kids on Friday, 15 kids on Saturday, and 9 kids on Sunday. How many more kids did she play with on Tuesday and Thursday combined than on Monday, Wednesday, and Sunday combined?
user