A man P has 7 friends, 4 of them are ladies and 3 are men, His wife Q also has 7 friends, 3 of them are ladies and 4 are men. Assume P and Q have no common friends. Then the total number of ways in which P and Q together can throw a party inviting 3 ladies and 3 men, so that 3 friends of each of P and Q are in this party, is