The radius of a cylinder base is 1 decimeter. If the base is divided into many equal sectors, then the cylinder is cut according to the radius of the sectors to form an approximate cuboid with the same base and height. The surface area of the cuboid is larger than that of the cylinder. The surface area is increased by 100 square decimeters, what is the original surface area?
一个圆柱底面半径为1分米，如把其底面分成许多相等的扇形，然后把圆柱按扇形的半径一一切开，拼成一个与它等底等高的近似长方体，长方体的表面积比圆柱的表面积增加了100平方分米，原来的表面积是多少？
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">100 / 2 / 1</gadget>
<output>50</output>

<gadget id="calculator">3.14 * 1 * 50</gadget>
<output>157</output>

<gadget id="calculator">6.28 + 157</gadget>
<output>163.28</output>

<result>163.28</result>