A building is 60 cm long, 50 m wide, and 70 m high. "July 1st" is coming soon, in order to add a festive atmosphere, we need to hang colored lights on the edge of the outer wall (not hanging along the ground). Uncle Zhang went to the store to buy colored lights. Each bundle is 100 meters long. How many bundles will he buy at least?
某建筑长60厘米，宽50米，高70米．"七一节"快到了，为增添节日气氛，要给外墙棱上挂彩灯(沿地面一圈不挂)，张叔叔去商店买彩灯，每捆100米，他至少买几捆？
<gadget id="calculator">70 * 4</gadget>
<output>280</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<gadget id="calculator">280 + 100 + 120</gadget>
<output>500</output>

<gadget id="calculator">500 / 100</gadget>
<output>5</output>

<result>5</result>