##### 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 40 7

### Sample Output

4