XVIII Open Cup named after E.V. Pankratiev. Grand Prix of Peterhof

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Xiejiadong: 抱着能 AK 的幻想。最后一个小时还是三人三线开题。三人枪机，三人三爆炸。

Problem A

Solved by Kilo_5723 01:10. (+3)

Problem B

Unsolved.

Problem C

Solved by Weaver_zhu. 01:18 (+)

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Problem D

Solved by Kilo_5723. 04:54 (+2)

Problem E

Solved by Xiejiadong. 02:01 (+)

Problem I

Solved by Xiejiadong. 00:27 (+)

Problem J

Upsolved by Weaver_zhu. (-8)

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题意：判断完全平方数。

题解：二次剩余随便判几个int范围素数就行了。