Combine 3 videos, into one

I have three videos, each of a different person who is walking around in each video.

I want, one single video showing a all 3 people in the video image at the same time. Each person being in a different third of the video images.

In the original videos, each person moves from left around. So it will mean you edit each video, so each person is never out of shot. Each video is about 30 seconds... so the final video will be about 30 seconds long also.

Please confirm how you will edit this and how long it will take you?
Thank you