Write a Python program that accepts a column number from the user and prints
"Yes" if it is 100% conserved and "No" otherwise. A 100% conserved column is
one that has the exact same nucleotide in every sequence. For example if the 
user enters 1 and the the multiple alignment below is given as input

>human
ACC
>mouse
ACC
>cat
TCC
>dog
ACA

then the output should be "No". But if the user enters 2 then the output
should be "Yes".

The sequence length may be different from three and the the number of
sequences can vary.

Submit your solution in class on Nov 18th.