Complex sentence: In the United States, the song song entered the Billboard Hot 100 chart at No.77 in December 2013, and continued climbing and reached No.19 in March 2014, and reached a million in total sales that week.
Split into simpler sentences: In the United States, the song song entered the Billboard Hot 100 chart at No.77 in December 2013. It continued climbing and rose to No.19 in March 2014, and reached a million in total sales that week.