Emuskald innovative musician try push boundary music production now come idea revolutionary musical instrument rectangular harpA rectangular harp rectangle nm consist n row m column the row number 1 n similarly column number 1 m leave right string pin space evenly unit thus n pin leave right side harp m pin the harp exactly nm different string string connect different pin different harpEmuskald order apprentice construct rectangular harp however do not mention string cross impossible play harp two string cross segment connect pin intersect to fix harp Emuskald perform operation type pick different column swap pin harp change pin connect string pick different row swap pin harp change pin connect string in follow example fix harp swap column help Emuskald complete creation find permutation row column harp need rearrange tell impossible he detach reattach string pin physical layout string do not matter