Puzzleup 2012 (14) Full Prime Number - 拼圖

題目網址: http://www.puzzleup.com/2012/?home
http://www.puzzleup.com/2012/puzzle/?255
答題時限: 10月25日７ＰＭ－比賽結束（約１２月１２日）
加分時限: 10月25日７ＰＭ－10月30日６：５９ＰＭ

答對可得基本分１００分。答案可上傳５次，每改１次答案從基本分扣２０分。
另有兩種加分： １. 加分時限內答對。例：第Ｎ天答對，可加（６－Ｎ）分。
２. 題目越困難，加分越多。例：這題有ｎ％的人答錯，答對者加ｎ分。

◆Full Prime Number

All the numbers that can be read with two or more adjacent digits inside a
prime number are also prime numbers. What is the greatest number having this
property?

Exampe:6173 is such a number. Because 61, 17, 73, 617, 173 and 6173 are prime
numbers

考慮所有如此的質數，當任意取出連續兩個或以上的位數所形成的數也都是質數。
此種數最大是多少？

例如 6173 即為此種數，因 61、17、73、617、173、6173 都是質數。

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又是簡單題了呢...

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'Oh, Harry, don't you see?' Hermione breathed. 'If she could have done
one thing to make absolutely sure that every single person in this school
will read your interview, it was banning it!'
---'Harry Potter and the order of the phoenix', P513

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