Nanro

Description
Nanro is a number placement logic puzzle where numbers must be entered into a grid.

Rules
The objective is insert numbers, subject to the following rules:


 * 1) Each area must contain at least one numbered cell.
 * 2) Numbers in some cells count the total of numbered cells in that area.
 * 3) Where two numbers connect across a boundary between areas, those numbers must be different.
 * 4) Numbers must form one, connected area with no 2x2 areas of numbered cells.

Example
A standard 10x10 nanro and its solution.