Write a function called flatten$\_$slice$\_$and$\_$multiply that has two inputs called Matrix$1$ and Matrix$2$ where each is represented as a numpy array. The function should reshape Matrix$2$ so that it is a vector $($i$.$e$.$ its shape is in the form $($x$,)),$ then it should slice Matrix$1($by removing the last z columns$)$ so that the product of the sliced Matrix$1$ and the reshaped Matrix$2$ is possible, and finally return the product. For this question, the number of elements in the reshaped Matrix$2$ will always be less than or equal to the number of columns in initial Matrix$1.$

For example, if the shape of Matrix$1$ were $(10,8)$ and the shape of Matrix$2$ were $(2,3),$ then the shape of the reshaped Matrix$2$ would be $(6,)$ and the shape of the sliced Matrix$1$ would be $(10,6).$