Final temperature of the gas mixture,neglecting heat losses

[Intekhab Alam]

A box containing 2 moles of rigid diatomic gas molecules at temperature T connected to another box containing 2 moles of ideal monoatomic gas at temperature 5T. What is the final temperature of the gas mixture,neglecting heat losses?
2. The attempt at a solution:
Q(initial)=Q(final)
m1C(v1)T(1)+m2C(v2)T(2)=(m1+m2)C(v)T(final)
but i don't know m1 & m2.

 

[BvU]

I read 2 moles for m1 and also for m2 ?!