Gildong buy famous painting software cfpaint the work screen cfpaint squareshape consist n row n column square cell the row number 1 n column number 1 n leave right the position cell row r column c represent r c there color cell cfpaint black whiteThere tool name eraser cfpaint the eraser integer size k 1 le k le n to use eraser Gildong need click cell j 1 le j le n k 1 when cell j clicked cell j le le k 1 j le j le j k 1 white in word square equal k cell leave corner j colored whiteA white line row column black cellsGildong work cfpaint time cell possibly zero currently black he want know maximum number white line eraser exactly help Gildong find answer question