3. Village Chief Slow Sheep writes down the natural numbers $1 \sim 100$ on the blackboard in sequence. Happy Sheep first erases the numbers that can be divided by 5, then Boiling Sheep erases the numbers that contain the digit 5, and Lazy Sheep erases the numbers whose sum of digits can be divided by 5. At this point, there are $\qquad$ numbers left on the blackboard.
$56$