N = gets.chomp.to_i

10000000
fizbuz = []

count = 0
for i in 1..10 ** 100
  if (i % 5 == 0 and i % 3 == 0 and /^[35]*$/ =~ i.to_s)
    count += 1
    if count == N
      puts i
      break
    end
  end
end