Hi Mingyi, On Fri, 2 Apr 2021 12:44:23 +0000 "Liu, Mingyi" <mingyiliu at gatech.edu> wrote: > Thanks for your reply but that doesn't answer the question. Yes, this > line "printf("%s%s%n\n", &a, &b, &c);" plays a significant role here, sorry, I misread the first n as s. Now it makes sense. Frank