$6-(25$ points$)$ Using p $=7$ and q $=11$ and e$=7$ and the RSA algorithm encrypt the following message that Bob is sending to Alice:

$$LET US HAVE COFFEE TOGETHER$$

Also, decrypt the same message to demonstrate that you obtain the same original plaintext and that Alice will be able to read it$.$

Remember: n $=$ p$*$q$,$ Phi$($n$)=($p$-1)*($q$-1)=60$ d $=$ e$^-1$ mod $60=7^-1$ mod $60=43$

Use Sagemath for the calculations

Cipher: P$^$e mod $77=$ C to decipher P $=$ C$^$d mod $77$