The pseudocode of the attack is the following.
We use fpylll (https://github.com/fplll/fpylll) in order to apply Babai's nearest plane algorithm.
So we shall import fpylll in sagemath. Babai's algorithm is a method of GSO in fpylll library.
For N=557,q=8192 we got the message with babai as a cvp oracle.
In the previous experiment we set count=100, i.e. we pick 100 different vectors E=(E_i), all having the propery
|E_i-c_i |<=38. In the second try, we found the message.
See attack.py