4.20 Ya'an Earthquake 52 Class 50 students organized donations, just divided into groups of 6 and 4, each group of 6 donated 100 yuan; each group of 4 donated 80 yuan. Please calculate how much is the minimum donation from Class 4 and Class 2 students?
4.20雅安地震五二班50名同学组织捐款，刚好分成6人与4人组，6人一组每组捐款100元；4人一组每组捐款80元．请你算一算四二班同学最少捐款多少元？
<gadget id="calculator">2 * 80</gadget>
<output>160</output>

<gadget id="calculator">100 * 7</gadget>
<output>700</output>

<gadget id="calculator">160 + 700</gadget>
<output>860</output>

<result>860</result>