<p>If I have one brother, and both parents, the answer is 4, right? M, F, S1, S2?</p>
<p>Just making sure that I do not make gross errors.</p>
<p>If I have one brother, and both parents, the answer is 4, right? M, F, S1, S2?</p>
<p>Just making sure that I do not make gross errors.</p>
<p>Yep. Four.</p>