You are given four integers
,
,
,
that satisfy the equations
and
, where
is a positive integer. Output all possible values of
. It is possible that there are none — in which case you do not need to output anything.
Constraints
For all subtasks:

and 
Points Awarded |
Additional Constraints |
3 points |
and  |
5 points |
 |
7 points |
No further constraints |
Input Specification
The only line of input contains four integers
,
,
and
.
Output Specification
Output all possible values of
, each on their own line and in ascending order.
Sample Input
Copy
13 1 10 2
Sample Output
Copy
4
Explanation for Sample
and
. It can be shown that this is the only possible value of
.
Comments