About this puzzle
Sudoku - also known as "Number Place" - is a logic-based, combinatorial number-placement puzzle. The aim of Sudoku is to enter a number from 1 through 9 in each cell of a grid, most frequently a 9×9 grid made up of 3×3 subgrids. Each row, column and region must contain only one instance of each number.
This Sudoku variant is called "Girandola Sudoku". It contains an extra group of nine marked cells. This group must also contain the numbers 1 through 9.