How much is the difference between "621-127-73" and "621-127+73"?
"621-127-73"和"621-127+73"的得数相差多少．
<gadget id="calculator">621 - 127</gadget>
<output>494</output>

<gadget id="calculator">494 + 73</gadget>
<output>567</output>

<gadget id="calculator">621 - 127 - 73</gadget>
<output>421</output>

<gadget id="calculator">567 - 421</gadget>
<output>146</output>

<result>146</result>