program str(input,output);
var
  str1,str2,str3:packed array[1..20] of char;
  i,he,jinwei:integer;
begin
  for i:=1 to 20 do read(str1[i]);
  for i:=1 to 20 do read(str2[i]);
  for i:=20 downto 1 do
    begin
      he:=ord(str1[i])-48+ord(str2[i])-48+jinwei;
      if he>9 then
                begin
                  jinwei:=1;
                  str3[i]:=chr(he-10+48);
                end
              else
                begin
                  jinwei:=0;
                  str3[i]:=chr(he+48);
                end;
    end;
    writeln(str3);
end.