gistfile1.txt

import sys

lines = open(sys.argv[1], 'r')

for line in lines:
    line = line.replace("\n", "").split(";")
    arr = line[0].split(",")
    n = int(line[1]);

    hsh = {}
    output = ""
    for x in arr:
        t = int(x)
        if str((n-t)) in arr and t is not (n-t):
            m = min(t, n-t)
            s = str(m) + "," + str(n-m)
            try:
                hsh[s]
            except:
                hsh[s] = True
                output = output + ";" + s
    print output[1:] or 'NULL'
lines.close()