Klebram are a social creature. When there aren't enough, they feel cold and unhappy; too many make them hot and unhappy. Klebram are happy when a group is between 40 and 60, inclusive. Except at night, when it is cool, in which case there is no upper limit on the number of Klebram; more make it warmer. Return true if the group of Klebram with the given values is happy, or false otherwise.