For some candies, if each student divides 15 pieces, there will be 3 less pieces, and if each student divides 18 pieces, there will be 3 less pieces. How many pieces of these candies are there at least?
一些糖果，如果每个学生分15粒则少3粒，如果每个学生分18粒也少3粒，这些糖果最少有多少粒？
<gadget id="calculator">2 * 3 * 3 * 5</gadget>
<output>90</output>

<gadget id="calculator">90 - 3</gadget>
<output>87</output>

<result>87</result>