Background: In addition, recording and reproducing an HDTV signal was a significant technical challenge in the early years of HDTV (Sony HDVS). Japan remained the only country with successful public broadcasting of analog HDTV, with seven broadcasters sharing a single channel.
Question: How many broadcasters did Japan have sharing a single channel?
Answer:<extra_id_0>.
<extra_id_0> seven<extra_id_1>