# Typo in texts of Codebook

**URL:** <https://discuss.pennylane.ai/t/typo-in-texts-of-codebook/3549>\
**Category:** Codebook\
**Created:** [October 13, 2023, 8:51pm UTC](https://discuss.pennylane.ai/t/typo-in-texts-of-codebook/3549 "2023-10-13T20:51:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Dhawal\_Verma](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/dhawal_verma/32/1996_2.png) [@Dhawal\_Verma](https://discuss.pennylane.ai/u/Dhawal_Verma)\
**Post date:** [October 13, 2023, 8:51pm UTC](https://discuss.pennylane.ai/t/typo-in-texts-of-codebook/3549/1 "2023-10-13T20:51:42Z")

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In the explanation of ‘The RSA system’ in Shor Algorithm section S.5, there is a typo in the value of d. It should be 27 and not 37. Hope you fix it @TeamXanadu

Explanation: The values of N and e are selected to be 55 and 3. Thus, p = 5 and q = 11

This gives theta = (5-1)\*(11-1) = 40

Now, d being the inverse of e = 3, with respect to mod 40, it should be equal to 27, as 27\*3 = 1 mod(40)

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**Author:** ![Guillermo\_Alonso](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/guillermo_alonso/32/816_2.png) [@Guillermo\_Alonso](https://discuss.pennylane.ai/u/Guillermo_Alonso)\
**Post date:** [October 16, 2023, 1:05pm UTC](https://discuss.pennylane.ai/t/typo-in-texts-of-codebook/3549/2 "2023-10-16T13:05:59Z")

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Hello, you are indeed right 🙂 It seems I took mod N but as you say, it is with respect to \theta. Thank you very much, we will change it soon!