Score : 300 points
There are N cities on a number line. The i-th city is located at coordinate x_i.
Your objective is to visit all these cities at least once.
In order to do so, you will first set a positive integer D.
Then, you will depart from coordinate X and perform Move 1 and Move 2 below, as many times as you like:
Find the maximum value of D that enables you to visit all the cities.
Here, to visit a city is to travel to the coordinate where that city is located.
Input is given from Standard Input in the following format:
N X x_1 x_2 ... x_N
Print the maximum value of D that enables you to visit all the cities.
3 3 1 7 11
2
Setting D = 2 enables you to visit all the cities as follows, and this is the maximum value of such D.
3 81 33 105 57
24
1 1 1000000000
999999999