Solved by rubytest

#	Title	# Solved	Avg. Tries
1000	A+B STANDARD	328,018	2.59
1001	A-B STANDARD	282,044	1.45
1008	A/B STANDARD	233,319	2.89
2557	Hello World STANDARD	362,304	2.54
10998	A×B STANDARD	235,489	1.30
16904	집합과 쿼리	41	1.98

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