Let $F_n$ be the nth fibonacci number where $F_0 = 0$ and $F_1 = 1$.

Also let a = $3^{3^{43}}$ and b = $3^{3^{42}}$.

If $F_x = gcd(F_a, F_b)$ where x can be represented as $27^y$.

If $(F_m)^3 - (F_n)^3 = F_y - (F_{y/3})^3$

Find the value of $(m*n) mod 1000000007$.