You are given an array of $n$ integers, and your task is to find four values (at distinct positions) whose sum is $x$ .
The first input line has two integers $n$ and $x$ : the array size and the target sum.
The second line has $n$ integers $a_1,a_2,\dots,a_n$ : the array values.
Print four integers: the positions of the values. If there are several solutions, you may print any of them. If there are no solutions, print IMPOSSIBLE .
8 15 3 2 5 8 1 3 2 3
· \n · · · · · · · \n
2 4 6 7
· · · \n