Point Distance

Given two points, find the direct distance between the points to the nearest integer.


Input Specification


The first line will consist of two integers \(X_1\) and \(Y_1\) (\(0\le |X_1|, |Y_1|\le 10^6\)) separated by a single space.

The second line will consist of two integers \(X_2\) and \(Y_2\) (\(0\le |X_2|, |Y_2|\le 10^6\)) separated by a single space.


Output Specification


The output will consist of one single line consisting of one integer, the nearest integer distance between the two points.


Sample Input


-3 4
0 7


Sample Output


4
Comments