FJ and his cows enjoy playing a mental game. They write down the
numbers from 1 to N (1 <= N <= 10) in a certain order and then sum
adjacent numbers to produce a new list with one fewer number. They
repeat this until only a single number is left. For example, one
instance of the game (when N=4) might go like this:
3 1 2 4
4 3 6
Behind FJ's back, the cows have started playing a more difficult
game, in which they try to determine the starting sequence from
only the final total and the number N. Unfortunately, the game is
a bit above FJ's mental arithmetic capabilities.
Write a program to help FJ play the game and keep up with the cows.
* Line 1: Two space-separated integers: N and the final sum.
* Line 1: An ordering of the integers 1..N that leads to the given
sum. If there are multiple solutions, choose the one that is
lexicographically least, i.e., that puts smaller numbers
3 1 2 4
There are other possible sequences, such as 3 2 1 4, but 3 1 2 4
is the lexicographically smallest.