class Calc0101
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @n = args.shift.first.to_i
    @k = args.shift.first.to_i
    @xys = args.map { |l| l.map(&:to_i) }
  end

  def run
    pattern = calc_pattern
    cycles = (1..@n).map { |k| calc_cycle(pattern, k) }
    cycles.inject { |a, b| a * b / a.gcd(b) }
  end

  def calc_cycle(pattern, k)
    c = 0
    s = k
    begin
      c += 1
      k = pattern[k - 1]
    end until s == k
    c
  end

  def calc_pattern
    (1..@n).map { |k| calc_amida(k) }
  end

  def calc_amida(k)
    i = -1
    loop do
      j = @xys.drop(i + 1).index { |x, y| x == k || y == k }
      break unless j
      i += j + 1
      k = @xys[i][0] == k ? @xys[i][1] : @xys[i][0]
    end
    k
  end
end

puts Calc0101.new(STDIN.readlines).run if __FILE__ == $0