Problem037

p037.rb

#! ruby
  
require 'prime'

ans = []
Prime.each do |n| 
  next if n < 10
  flag = true
  l = n.to_s.split(//)
  until l.empty?
    flag = false unless Prime.prime?(l.join.to_i)
    l.shift
  end
  r = n.to_s.split(//)
  until r.empty?
    flag = false unless Prime.prime?(r.join.to_i)
    r.pop
  end
  ans << n if flag
  break if ans.size == 11
end
  
p ans.inject(:+)