A method for writing data, the method may include evaluating current levels of multiple memory cells that belong to a certain set of memory cells or receiving an indication about the current levels of the multiple memory cells; encoding a new data unit to provide an encoded data unit to be written to the multiple memory cells while minimizing an amount of changes in levels of the maximum cell level among the multiple memory cells required for storing the encoded data unit; and writing the encoded data unit to the multiple memory cells.