The first line of the input file contains two whole numbers M and N separated by a space character, 1
≤ M, N ≤ 100 000, where M is a length of a segment and N is a number of damages occurring on the
highway.
The second line contains N whole numbers separated by a space character representing the positions of
all damages. Each of those numbers is greater than M and less than or equal to 2 000 000 000 (two
billion). The sequence of N numbers given in the second line will always be strictly increasing sequence.
The first line of the output file should contain the minimal number of damage fixing teams.
The second line should contain all the positions where the first segment can begin. These numbers
should be separated by a space character and they must form a strictly increasing sequence.
