import java.lang.Math.*;

public class Line {

public static void main(String[] args){

// java Line x1 y1 x2 y2

final int x = Math.abs(Integer.parseInt(args[0])-Integer.parseInt(args[2]));

final int y = Math.abs(Integer.parseInt(args[1])-Integer.parseInt(args[3]));

int total = 0;

for (int m = 1; m < (int) Math.sqrt(x); m++)

for (int n = 1; n < m; n++)

if (2*m*n*x == y*(m*m - n*n)) {

total++;

break;

}

System.out.println(total);

}

}

/*

* Write a program that takes as its input four integers, representing two

* points A and B in a plane with integer coordinates, and outputs the number

* of points with integer coordinates that are on the line segment AB.

*

* Find how many sets of integers (a,b,c) satisfy,

*

* a <= x = |x2-x1| and b <= y = |y2-y1| where

* k(a^2 + b^2) = k*c^2

*

* Use Pythogorean triples: a = m^2 - n^2, b = 2mn, (c = m^2 + n^2) where m > n.

*

* b/a = y/x => 2mn /(m^2 - n^2) = y/x => 2mx = y(m^2 - n^2).

*

* Since m^2 - n^2 <= x, m < floor (Math.sqrt (x)).

* */