A group of children buy two commodities with prices of 3 yuan and 5 yuan. The minimum quantity purchased by each person is one piece. They can also buy the same product. However, the total purchase amount per person should not exceed 15 yuan. If at least three of the children purchased the same amount of the two products, how many children are there at least in this group?
一群小朋友购买售价是3元和5元的两种商品．每人购买的数量最少是一件．他们也可购买相同的商品．但每人的购买总金额不得超过15元，若小朋友中至少有三人购买的两种商品的数量完全相同，问这群小朋友最少有多少人？
<gadget id="calculator">2 * 12</gadget>
<output>24</output>

<gadget id="calculator">24 + 1</gadget>
<output>25</output>

<result>25</result>