A tennis club has 16 men and 21 women in it. There are 6 married couples in the club. A team of 6 has to be chosen for a tournament that includes 3 of each sex. How many possible teams of 6 can be chosen if it cannot contain any married couple?

I've tried to get the answer that is provided, but my calculations are off somewhere. The answer is meant to be 629070, but I'm getting 637

790 and I'm not sure where the problem lies. Thanks for any help!