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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def check_files_exist(filenames):
    '''Dies if any files in the list of filenames does not exist'''
    files_not_found = [x for x in filenames if not os.path.exists(x)]
    if len(files_not_found):
        for filename in files_not_found:
            print('File not found: "', filename, '"', sep='', file=sys.stderr)
        raise Error('File(s) not found. Cannot continue')