FFMPEG Concat Demuxer adds more time to video than expected

I am using ffmpeg concat demuxer to join multiple(189) videos together.
The videos are originally split from a single video using the following command:

ffmpeg -ss time[2] -vsync 1 -copyts -i inputfile.mp4 -ss time[0] -to time[1] -c:a copy -c:v libx264 -b:v 800k output.mp4

Thereafter I am using the following concat command:

ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4

The problem is that the sum of the lengths of the input videos is 24:03:520
The output.mp4 video comes out to be 24:05:550.
Which is two seconds longer than the constituent video length.

I need the output video to be time accurate. How can I achieve this without reencoding the video?