DVD and a napkin

And what will happen if the problem Marinka "DVD and slut" накроет all scattered disks just one napkin? Of course, the napkin she should choose the smallest possible size!

Input In the first line of input data recorded four integers:

• X, Y - the size of the table horizontally and vertically (0 < X, Y ≤ 1000),

• R - radius of one disc DVD (0 < R ≤ 1000),

• N - number of discs on the table (0 ≤ N ≤ 1000).

Then follow N lines, each of which contains x[i], y[i] - coordinates of the entire center of the disk. It is guaranteed that all wheels are on the table and not hang over the edge of the table. Output Display area of the table, free from a rectangular sheet, nakryvayuschkgo all drives.

Examples