require 'primesieve'

BASE_36 = %w(0 1 2 3 4 5 6 7 8 9 a b c d e f j h i j k l m n o p q r s t u v w x y z)

def to_36(num)
  res = ''
  while num > 0
    res += BASE_36[num % 36]
    num /= 36
  end
  res
end

def main(prime_count)
  length = 0
  prev = ''
  i = 0
  p 'inside main'
  Primesieve.generate_n_primes(prime_count, 0).each do |prime|
    res = to_36(prime)
    length += res.size
    i += 1
    next if i < 1_500_000_000
    comb = prev + res
    p "#{res} perc: #{ 100.0*i / prime_count}" if i % 100_000 == 0
    if comb.include?('iparty')
      p '================================= BINGO =========================='
      p length
      p comb
      p length + comb.index('iparty')
      return
    else
      prev = comb.size < 5 ? comb : comb[comb.size-5, comb.size-1]
    end
  end
  p "Length of processed: #{length}"
end

main(2_000_000_000)