A cube is placed on the table, with a number written on each side, and the sum of the two numbers on the opposite side is equal to 15. Xiao Ming can see the top and two sides, and the sum of the three numbers he sees is 22; Xiao Gang can see the top surface and the other two sides, and the sum of the three numbers he sees is 24. What is the number on the top?
一个正方体木块放在桌子上，每一面都写有一个数，相对的面两个数的和都等于15，小明能看到顶面和两个侧面，看到的三个数之和为22；小刚能看到顶面和另外两个侧面，看到的三个数之和为24．顶面的数是几？
<gadget id="calculator">22 + 24</gadget>
<output>46</output>

<gadget id="calculator">15 + 15</gadget>
<output>30</output>

<gadget id="calculator">46 - 30</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<result>8</result>