Choose 8 different numbers from the ten numbers from 0 to 9 to form two four-digit numbers. What is the smallest difference that can be obtained? (difference is non-negative)
从0～9这十个数字中选出8个不同的数字，组成两个四位数，所能得到的最小的差是多少．(差为非负数)
<gadget id="calculator">5_012 - 4_876</gadget>
<output>136</output>

<result>136</result>