When the school dance team rehearses, if there are 4 people in each row, there will be no leftovers; if there are 5 people in each row, there will be 4 people left; if there are 6 people in each row, there will be 4 people left. At least how many people participated in the rehearsal?
学校舞蹈队同学排练，如果每排4人，正好没有剩余；如果每排5人，余4人；如果每排6人，余4人．参加排练的至少有多少人？
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">60 + 4</gadget>
<output>64</output>

<result>64</result>