In response to the call of "planting trees and greening barren hills", the students in class A1 went down to plant trees on the hillside under the leadership of the teacher. After planting, the teacher asked the students to count how many trees they had planted, and found: 2 trees 2 1 tree left, 3 trees, 3 trees, 2 trees, 4 trees, 4 trees, 3 trees, 5 trees, 5 trees, 4 trees, 6 trees, 6 trees 5 trees, then how many trees did they plant at least.
为了响应"植树造林，绿化荒山"的号召，A1班的同学在老师的带领下去山坡上种树，种完后，老师让同学们数数一共种了多少棵树，结果发现：2棵2棵地数还剩1棵，3棵3棵地数还剩2棵，4棵4棵地数还剩下3棵，5棵5棵地数还剩4棵，6棵6棵地数还剩的5棵，那么他们至少种了多少棵．
<gadget id="calculator">3 * 4 * 5</gadget>
<output>60</output>

<gadget id="calculator">60 - 1</gadget>
<output>59</output>

<result>59</result>