private static void addTwoFactors(long[] primes, List<Long> set) {
		for (int i = 0; i < primes.length; i++) {
			if (i%100 == 0)
				System.out.println(i + " two");
			long p1 = primes[i];
			if (p1 > 5 && !(p1 % 6 == 1 || p1 % 6 == 5))
				continue;
			for (int j = i+1; j < primes.length && primes[i]*primes[j] <= limit; j++) {
				long p2 = primes[j];
				long n = p1*p2;
				
				if ((n-1) % (n-(p1-1)*(p2-1)) == 0) {
					set.add(n);
				}
			}
		}
	}