ntrials = 100000
res = rep(0,ntrials)
tot = 0
for (j in 1:ntrials)
{
  nflips = 50 
  trial = rbinom(nflips, 1, .5)
  maxRun = max(rle(trial)$lengths)
  tot = tot+(maxRun >= 8)
}
m = tot/ntrials
cat(m)