There are 3 children, one of them happens to be 1 year older than the other, and the product of their ages is 504. Q: How old is the youngest child?
有3个小朋友，他们的年龄恰好是一个比一个大1岁，他们年龄的积是504．问：最小的小朋友几岁？
<result>7</result>