there time recall good old friend you ve come luckily social network store message history make easy know argue 10 year agomore formal message history sequence message order time send number 1 n n total number message chateach message contain link early message reply when open message x get link dialogue show way k previous message message x k message visible respect message x in case k message showndigge deep message history read visible message link current message x continue read mannerdetermine number message you ll read start message number t t 1 n Calculate number independently if start message x initial configuration x k previous k message message read multiple time consider