i am testing the direct and indirect effect of x on y and i have three mediators (M1, M2, M3), however M1 and M2 , are parallel mediators and don't have a causative effect between each other but both together (m1,m2) have a causative effect on M3 or in other words, they both together leads to or predicts M3 and then M3 leads to Y.

(X >> (M1,M2) >> M3>> Y)

so what the model that could fit that situation??

thanks