Sarah is tracking her exercise routine for the week. On Monday, she jogged 3 kilometers, on Tuesday, she jogged 4 kilometers, on Wednesday, she jogged 5 kilometers, and on Thursday, she jogged 6 kilometers. How many kilometers does she need to jog on Friday so that her average jogging distance for the five days is exactly 5 kilometers? Let's think step by step and output the final answer within \boxed{}.
user