PAR

def two_way_partition(a):
    '''Performs a 2-way partition on the array a.'''
    # Trivial with list comprehensions.
    return [x for x in a[1:] if x <= a[0]] + [a[0]] + [x for x in a[1:] if x > a[0]]


def main():
    '''Main call. Reads, runs, and saves problem specific data.'''
    # Read the input data.
    with open('C:/Users/User/Downloads/rosalind_par.txt') as input_data:
        input_data.readline()  # Don't need the first line.
        a = map(int, input_data.readline().strip().split())

    # Perform the 2-way partition.
    a = map(str, two_way_partition(a))

    # Print and save the answer.
    #print ' '.join(a)
    with open('C:/Users/User/Downloads/Algorithmic_013_PAR.txt', 'w') as output_data:
        output_data.write(' '.join(a))

if __name__ == '__main__':
    main()