#!/usr/bin/python

import sys
from math import sqrt
from unique import unique

def factorize(n):
    def isPrime(n):
        return not [x for x in xrange(2,int(sqrt(n))+1) if n%x == 0]
    primes = []
    candidates = xrange(2,n+1)
    candidate = 2
    while not primes and candidate in candidates:
        if n%candidate == 0 and isPrime(candidate):
            primes = primes + [candidate] + factorize(n/candidate)
        candidate += 1
    return primes

def divisors(n):
        divisors = 1
        factors = factorize(n)
        candidates = unique(factors)
        for candidate in candidates:
                divisors = divisors * (factors.count(candidate)+1)
        return divisors

def t(n):
        return ((n*(n+1))/2) 

i = 2

while divisors(t(i)) < 500:
        i = i + 1

print t(i)