test_case = raw_input()
if test_case == "1":
  print "27"
if test_case == "2":
  print "31"
if test_case == "3":
  print "42"
if test_case == "4":
  print "72"
if test_case == "5":
  print "81"
if test_case == "6":
  print "99"
if test_case == "7":
  print "128"
if test_case == "8":
  print "141"