{HEAD ~ A video synthesizing apparatus} configured to receive {TAIL ~ a first video} and a second video and output the first video synthesized with the second video, wherein, 
configured to receive
{ HEAD ~ A video synthesizing apparatus } configured to receive { TAIL ~ a first video } and a second video and output the first video synthesized with the second video , wherein ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH