Here is my code. When compiling using g++ 12.1.0 on my local machine or using GNU G++ 20 on the judging machine, it always stop the input after the first loop of the first loop. Like it showns here. With the debug code, it output something like 5 ? 1 1 > g 1- ? 2 1 2 > 2 ? 1 2 > u 1- ! gu??? where lines start with > is my input.

But when compiling with Clang++ on my local machine or on judge machine, it works well.

P.S. please ignore the WA on clang++, it is caused by making too many queries, which can be solved using binary search but I've not implement that yet.