grt = max_hrt
        ch = 0
        dm = 0
        error_y = sy
        dT = max_hrt / 2

        while True:
            alpha = k*grt
            reached = max_hr + g * (k*alpha - e**alpha + 1) / k**2
            if (-error_y < reached < error_y):
                break
            if (reached > error_y): #Not enough
                if (dm == 2):
                    ch += 1
                dm = 1
                grt = grt + (dT / 2**ch)
            if (reached < -error_y): #Too much
                if (dm == 1):
                    ch += 1
                dm = 2
                grt = grt - (dT / 2**ch)