require'prime'
m=5000001
gets
b=0
gets.split.map{|a|b|=1<<a.ord-48}
c=0
l=0
z=1
Prime.each(m+10){|x|
  c<b||z=[z,[x,m].min-l].max
  (c=0;l=x)if x.to_s.each_char.any?{|y|
    c|=1<<y.ord-48
    (b|c)>b
  }
}
p z-2