program medium;
var     a,b,sout:longint;
        i:longint;

function sum(nr:longint):longint;
var
        i:byte;
        s:longint;
begin
        s:=0;
        while nr>0 do begin
                s:=nr mod 10 + s;
                nr:=nr div 10;
        end;
        sum:=s;
end;
begin
        writeln('a= ');
        readln(a);
        writeln('b= ');
        readln(b);
        sout:=0;
        for i:=a to b do
                if (i mod 2=1) then sout:=sout+ sum(i);
        writeln(sout);
end.