제출 #120069

3 1 1
2 3

런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.TreeSet.iterator()" because "<local1>" is null
	at Main.dfs(Main.java:55)
	at Main.main(Main.java:40)

1 
1 

3 2 3
1 2
1 2

런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.TreeSet.iterator()" because "<local1>" is null
	at Main.dfs(Main.java:55)
	at Main.main(Main.java:40)

3 
3 

3 3 3
2 1
2 1
1 2

런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.TreeSet.iterator()" because "<local1>" is null
	at Main.dfs(Main.java:55)
	at Main.main(Main.java:40)

3 
3