Use a rope on the bridge to measure the height of the bridge. When the rope is folded in half and hangs to the water surface, there is still 5 meters left, and when the rope is folded in three, there is still 2 meters left when it hangs to the water surface. Find the height of the bridge and the length of the rope.
在桥上用绳子测量桥的高度，把绳子对折后垂到水面时还余5米，把绳子3折后垂到水面还余2米．求桥高和绳长．
<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">8 + 10</gadget>
<output>18</output>

<result>18</result>