12. 8 girls and 25 boys stand in a circle, with at least two boys standing between any two girls. Therefore, there are $\qquad$ different arrangements (arrangements that can be made identical by rotating the circle are considered the same).
First, let each girl form a group with two boys (the arrangement is "girl-boy-boy"). Fix the group with girl $A$ at the first position, then there are 7 remaining groups and 9 boys for a total of 16 positions, with $C_{16}^{7}$ ways; then let the remaining girls and boys take their respective positions, with $7! \cdot 25!$ ways. Therefore, there are a total of $C_{16}^{7} \cdot 7! \cdot 25! = \frac{16! \cdot 25!}{9!}$ different arrangements.