Query to sum duplicated fields

Here is mysql data

id usr good quant delayed   cart_ts 
    ------------------------------------------------------
14  4   1   1   0   20100601235348
13  4   11  1   0   20100601235345
12  4   4   1   0   20100601235335
11  4   1   1   0   20100601235051
10  4   11  1   0   20100601235051
9   4   4   1   0   20100601235051
15  4   2   1   0   20100601235350
16  4   7   1   0   20100602000537
17  4   3   1   0   20100602000610
18  4   3   1   0   20100602000616
19  4   8   1   0   20100602000802
20  4   8   1   0   20开发者_如何学Go100602000806
21  4   8   1   0   20100602000828
22  4   8   1   0   20100602000828
23  4   8   1   0   20100602000828
24  4   8   1   0   20100602000828
25  4   8   1   0   20100602000828
26  4   8   1   0   20100602000829
27  4   8   1   0   20100602000829
28  4   9   1   0   20100602001045
29  4   10  1   0   20100602001046

I need to group fields in witch usr & good has duplicated values with summing quant field for getting smth like this:

id usr good quant delayed   cart_ts 
    ------------------------------------------------------
14  4   1   2   0   20100601235348
13  4   11  2   0   20100601235345
12  4   4   2   0   20100601235335
15  4   2   1   0   20100601235350
16  4   7   1   0   20100602000537
17  4   3   2   0   20100602000610
19  4   8   9   0   20100602000802
28  4   9   1   0   20100602001045
29  4   10  1   0   20100602001046

Which MySQL query I need to do to have this effect?

---

SELECT id,usr,good,SUM(quant),delayed,cart_ts FROM table GROUP BY usr,good