def MatrixNew (NC,NR,val=0):
    return[[val for col in range (NC)] for row in range (NR)]

def ProdMatrix (x,y):
    rowx=len(x)
    colx=len(x[0])
    rowy=len(y)
    coly=len(y[0])
    if colx != rowy:
        raise Exception("Impossibile")
    z=MatrixNew(rowx, coly)
    for i in range (rowx):
        for j in range (colx):
            for k in range (coly):
                z[i][k]+=x[i][j]*y[j][k]
    return printmatrix(z) #stampa in colonna