Calculation: 20131*2012120121-20121*2013120131.
计算：20131*2012120121-20121*2013120131．
<gadget id="calculator">20_131 * 2_012_120_121</gadget>
<output>40_505_990_155_851</output>

<gadget id="calculator">20_121 * 2_013_120_131</gadget>
<output>40_505_990_155_851</output>

<gadget id="calculator">40_505_990_155_851 - 40_505_990_155_851</gadget>
<output>0</output>

<result>0</result>