"""
Problem

A string is simply an ordered collection of symbols selected from some alphabet and
formed into a word; the length of a string is the number of symbols that it contains.

An example of a length 21 DNA string (whose alphabet contains the symbols 'A', 'C',
'G', and 'T') is"ATGCTTCAGAAAGGTCTTACG."

Given: A DNA string s of length at most 1000 nt.

Return: Four integers (separated by spaces) counting the respective number of times
that the symbols 'A', 'C', 'G', and 'T' occur in s.

Sample Dataset

AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC
Sample Output

20 12 17 21
"""

def dna():
    s = open("rosalind_dna.txt").read()
    for let in "ACGT":
        print s.count(let),
    print ''
