Xiao Ding Ding and Xiao Qiao typed 2,400 characters together. Xiao Ding Ding typed 56 characters per minute and could complete the task in 20 minutes. How many characters per minute did Xiao Qiao type?
小丁丁和小巧合打2400个字，小丁丁每分钟打56个字，20分钟可以完成任务，小巧每分钟打多少个字？
<gadget id="calculator">2_400 / 20</gadget>
<output>120</output>

<gadget id="calculator">120 - 56</gadget>
<output>64</output>

<result>64</result>