On the day of the Double Ninth Festival, Hengfeng Tea House invited 5 old people to taste tea. The ages of these 5 old people happened to be 5 consecutive natural numbers, and the sum of their ages was exactly 400. How old is the youngest among them?
重阳节那天，恒丰茶庄请来5位老人品茶，这5位老人的年龄恰好是5个连续的自然数，并且年龄之和恰好是400．其中年龄最小的老人有多少岁．
<gadget id="calculator">400 / 5</gadget>
<output>80</output>

<gadget id="calculator">80 - 2</gadget>
<output>78</output>

<result>78</result>