APMO'14 4 - brute force Python

import itertools,math

n=8
b=100


def isCorrect(zbior):
    sumy = set()
    for i in range(1,n+1):
        for kombi in itertools.combinations(zbior, i):
            #print kombi
            sumka = 0
            for e in kombi:
                sumka+=e
            if sumka in sumy:
                return False#there exists a duplicate sum
            sumy.add(sumka)
    return True#no duplicates

total = 100.0/(math.factorial(b)/(math.factorial(n)*math.factorial(b-n)))
counter = 0
ok=False
for z in itertools.combinations(range(1,b+1),n):
    counter+=1
    if counter%70==0:
        print (counter*total),"%       \r",
    if isCorrect(z):
        print "\n",z,"       "
        ok=True
        break#we only need one
if not ok:
    print "\nNone exist"