nth = int(raw_input('enter number nth: '))
oddprimes = [2]
cont = 2
candidat = 3
while (cont <= nth): #start with nth>=2
verificator = True
for i in oddprimes:
if candidat%i == 0:
verificator = False
break
if verificator:
oddprimes = oddprimes + [candidat]
cont = cont + 1
candidat = candidat + 2
print oddprimes[nth-1]
bnRoID0gaW50KHJhd19pbnB1dCgnZW50ZXIgbnVtYmVyIG50aDogJykpCm9kZHByaW1lcyA9IFsyXQpjb250ID0gMgpjYW5kaWRhdCA9IDMKd2hpbGUgKGNvbnQgPD0gbnRoKTogI3N0YXJ0IHdpdGggbnRoPj0yCgl2ZXJpZmljYXRvciA9IFRydWUKCWZvciBpIGluIG9kZHByaW1lczoKCQlpZiBjYW5kaWRhdCVpID09IDA6CgkJCXZlcmlmaWNhdG9yID0gRmFsc2UKCQkJYnJlYWsKCWlmIHZlcmlmaWNhdG9yOgoJCW9kZHByaW1lcyA9IG9kZHByaW1lcyArIFtjYW5kaWRhdF0KCQljb250ID0gY29udCArIDEKCWNhbmRpZGF0ID0gY2FuZGlkYXQgKyAyCnByaW50IG9kZHByaW1lc1tudGgtMV0=