If f(x) and g(x) are two polynomials such that the polynomial P (x)=f(x^3)+x g(x^3) is divisible by x^2+x+1, then P (1) is equal to \ \ \ \.

If $\displaystyle f(x)$ and $\displaystyle g(x)$ are two polynomials such that the polynomial $\displaystyle \mathrm{P}(x)=f\left(x^3\right)+x g\left(x^3\right)$ is divisible by $\displaystyle x^2+x+1$, then $\displaystyle \mathrm{P}(1)$ is equal to \_\_\_\_.