Yugioh unity question 10pts?

If I have 3 face up cards lets say stone statue of the aztecs def 2000, stealth bird def 1700 and exxod master of the guard def 4000. if I activate unity and choose stone statue of the aztecs would its def go up by 5700 because it only combines stealth bird and exxod or would it go up by 7700 because it facters in aztec's def. causing it to go to 9700 def? please help