Problem Description
For a given positive integer n, please find the smallest positive integer x that we can find an integer y such that y^2 = n +x^2.
Input
The first line is an integer T, which is the the number of cases.
Then T line followed each containing an integer n (1<=n <= 10^9).
Output
For each integer n, please print output the x in a single line, if x does not exit , print -1 instead.
Sample Input
2
2
3
Sample Output
-1
1
http://blog.csdn.net/libin56842/article/details/16919757
http://blog.csdn.net/hnust_xiehonghao/article/details/7864045