class SAU:
    def __init__ (self, zn_param):
        self.param = zn_param
        self.ypr = [0, 0]

    def zdn_zn(self, upr):
        self.x = upr

    def model(self):
        def inerz(x, T, yy):
            return (x + T * yy) / (T + 1)

        y0 = self.x - self.ypr[1] * self.param[3]
        y1 = self.param[0] * y0
        y2 = inerz(y1, self.param[1], self.ypr[0])
        y3 = inerz(y2, self.param[2], self.ypr[1])
        self.ypr[0] = y2
        self.ypr[1] = y3

    def otobrazh(self):
        print("y =", self.ypr[1])