Before attempting the problems below make sure you can do all the homeworks
from scratch on your own.

1. Write a Python script that prints "Yes" if two DNA sequences have the same
number of A's and "No" otherwise. The sequences are given in FASTA format
in a file called dna.txt.

2. Write a Python script that takes as input from the user a DNA sequence and
prints the name of the sequence if it is found in dna.txt given in FASTA format.

3. Write a Python script that takes as input from the user a DNA sequence and
prints "Yes" if it is a substring of any one of the sequences in dna.txt given
in FASTA format.