A piece of rectangular paper with a length of 6 cm and a width of 2 cm is rolled into a cylinder, and the volume of the cylinder obtained is the largest.
用一张长6厘米，宽2厘米的长方形纸卷成一个圆柱，按以多少厘米作为圆柱的高方式卷，得到的圆柱体积最大．
<result>2</result>