제출 #132090

2
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2 1

1
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8
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런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.HashSet.isEmpty()" because the return value of "java.util.HashMap.get(Object)" is null
	at Main.main(Main.java:47)

7

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10 2
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9 4
5 1
2 9

런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.HashSet.isEmpty()" because the return value of "java.util.HashMap.get(Object)" is null
	at Main.main(Main.java:47)

9

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2 4
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1 9
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7 5
6 7
1 5
6 8
2 9
3 6
5 8
3 1
8 1
9 4

런타임 에러 (RTE)
stderr:
 Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.util.HashSet.isEmpty()" because the return value of "java.util.HashMap.get(Object)" is null
	at Main.main(Main.java:47)

9