This puzzle was developed by Inaba Naoli.
Puzzle and Goal
An unsolved puzzle consists of a square grid. Some cells contain circles, circled numbers, or X.
The goal is to put circled numbers in some of the cells, according to the rules.
The solved grid must satisfy the following conditions:
Each circle must contain a number.
Each number must appear exactly once in each row and column.
Cells with initial X may not contain numbers (hence there may be empty cells as well).