program HelloWorld;

var i,c: integer;
    f: Real;

begin
    randomize;
    f := 0.0;
    for i := 1 to 10 do
    begin
        c := random(256);
        if ((c >= ord('A')) and (c <= ord('Z'))) or ((c >= ord('a')) and (c <= ord('z'))) then
            f := f + 1;
    end;

    writeln((f / 10 * 100):0:3, ' %');
end.