A certain class of students stood in a double-layer hollow square formation in the military training queue performance, and there were 9 students standing on each side of the outer layer. If the students in this class are asked to stand guard on a 250-meter-long straight road, starting from one end and standing every 5 meters, how many people will be left after the station is full?
某班同学在军训队列表演中恰站成一个双层空心方阵，外层的每边站了9名同学．若让这个班同学在一条250米长的笔直马路上站岗，从一端开始每隔5米站一人，则站满之后还剩下多少人？
<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">8 + 6</gadget>
<output>14</output>

<gadget id="calculator">14 * 4</gadget>
<output>56</output>

<gadget id="calculator">250 / 5</gadget>
<output>50</output>

<gadget id="calculator">50 + 1</gadget>
<output>51</output>

<gadget id="calculator">56 - 51</gadget>
<output>5</output>

<result>5</result>