Perfect numbers#848
A number is called perfect if it equals the sum of all its divisors smaller than itself. Find all the perfect numbers from to .
The first line contains and separated by a space.
and are integers; 1 \leq M \leq N \leq 10^9; (N - M) \cdot \sqrt{N} \leq 10^7.
Output each perfect number in ascending order, one per line. If there are no perfect numbers in the interval, output Absent.
Example 1