require'prime'
m=2048
n=gets.to_i
l=Array.new(n+1){{0=>0}}
(2..n).each{|i|
  r=s=0
  t=1
  Prime.each(i){|q|
    i%q>0?0:(r=q;s|=t)
    t*=2
  }
  l[r][s%m]=i
}
f=[0]*m
l.each{|k|
  f=(0...m).map{|x|
    k.map{|s,i|
      s>(x&s)?0:f[x^s]+i
    }.max
  }
}
p f.max