The monkey picked peaches. On the first day, it picked more than half of the peaches, but on the second day, it picked half of the remaining peaches and one less. At this time, there were still 15 peaches on the tree. How many peaches were there on the tree?
猴子摘桃，第一天摘了桃子的一半多1个，第二天又摘了余下桃子的一半少1个，这时树上还有15个桃子，原来树上有多少个桃子？
<gadget id="calculator">15 * 2 * 2</gadget>
<output>60</output>

<result>60</result>