์ ์ด 1,2,3,4 ์žˆ์œผ๋ฉด

1 -> (2,3) -> (3,4),(2,4)

๊ฐ™์€์‹์œผ๋กœ ํŠ•๊ธฐ๋Š” ๋А๋‚Œ์ž„