Class 1 of the fifth grade carried out the activity of "giving one book to read hundreds of books". Yang Kun brought all his extracurricular books. If divided into 3 groups, there would be 1 more book; Group, there are 5 more copies. Do you know how many books he has donated at least?
五年级一班开展了"献一本书看百本书"的活动，杨坤同学拿来了自己全部的课外书，如果分成3组还多1本；分成6组，多4本；分成7组，多出5本．你知道他一人至少捐了多少本书吗？
<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">42 - 2</gadget>
<output>40</output>

<result>40</result>