In the alphabet of the language of the tribe «tumba-yumba» four letters: "K", "L", "M" and "N". We need to display all possible words consisting of
n letters that contain at least two identical letters, not necessarily adjacent. The program should not build other words that do not match the condition.
| Input |
Output |
| 2 |
KK
LL
MM
NN
|
(c) K.Yu. Polyakov