f n
= 2 :
[4, 6 .. m
] where m
= if even n
then n
else n
- 1g n
= [2,4..m
] where m
= if (odd n
) then n
-1 else n
main
= mapM_ p
[0, 1, 2, 3, 4, 5, 6, 7]
ZiBuID0gMiA6IFs0LCA2IC4uIG1dIHdoZXJlIG0gPSBpZiBldmVuIG4gdGhlbiBuIGVsc2UgbiAtIDEKZyBuID0gWzIsNC4ubV0gd2hlcmUgbSA9IGlmIChvZGQgbikgdGhlbiBuLTEgZWxzZSBuCgpwIG4gPSBwdXRTdHJMbiAkIHNob3cgbiArKyAiID0gIiArKyBzaG93IChmIG4pICsrICIgPSAiICsrIHNob3cgKGcgbikKCm1haW4gPSBtYXBNXyBwIFswLCAxLCAyLCAzLCA0LCA1LCA2LCA3XQ==
0 = [2] = []
1 = [2] = []
2 = [2] = [2]
3 = [2] = [2]
4 = [2,4] = [2,4]
5 = [2,4] = [2,4]
6 = [2,4,6] = [2,4,6]
7 = [2,4,6] = [2,4,6]