You can do that by merging them together using a video joiner software. You can try these freeware List Of Best Free Video Joiners s . Not two you can join more than two videos together. These software support a lot video formats like MP4 MOV AVI FLV etc. You can also use a free video editor like HITFILM EXPRESS OpenShot Shotcut VSDC Free Video Editor etc. These software provide a timeline. So you can drag videos to tracks on timeline and merge them in one video.