 The Saxon grades use Roman numerals to denote the level of difficulty and subdivisions from grade VII onwards with the aid of the letter "a", "b" and "c"; "XIc" is currently the highest grade.In addition the system accounts for horizontal jumps with Arabic numerals between 1 and 7.The French numerical system (distinct from the adjectival system, described later) rates a climb according to the overall technical difficulty and strenuousness of the route.