class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: C = None
        self.z: B = None
        self.t: D = None
        self.w: E = None
        self.p: B = None
        self.r: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.y: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: H = None
        self.u: F = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.w: B = None
        self.x: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: A = None
        self.r: F = None
        self.v: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.y: C = None
        self.x: D = None
        self.w: C = None
        self.v: B = None
        self.t: C = None
        self.p: E = None
        self.u: A = None
        self.txt = txt

c = A("c")
d = B("d")
k = C("k")
n = D("n")
b = E("b")
f = F("f")
e = G("e")
l = H("l")
j = F("j")

c.x = n
c.t = n
c.u = k
c.z = d
c.p = d
c.r = d
c.w = b
d.u = n
d.y = k
k.v = n
k.s = n
k.y = l
k.u = j
n.v = b
n.w = d
n.x = e
b.q = l
f.y = j
f.r = j
f.p = c
f.v = n
e.x = f
l.o = e
l.y = k
l.w = k
l.t = k
l.x = n
l.v = d
l.p = b
l.u = c
j.y = f
j.r = f
j.p = c
j.v = n
assert c.z.y.u.txt == "
class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: C = None
        self.z: B = None
        self.t: D = None
        self.w: E = None
        self.p: B = None
        self.r: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.y: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: H = None
        self.u: F = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.w: B = None
        self.x: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: A = None
        self.r: F = None
        self.v: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: G = None
        self.y: C = None
        self.x: D = None
        self.w: C = None
        self.v: B = None
        self.t: C = None
        self.p: E = None
        self.u: A = None
        self.txt = txt

c = A("c")
d = B("d")
k = C("k")
n = D("n")
b = E("b")
f = F("f")
e = G("e")
l = H("l")
j = F("j")

c.x = n
c.t = n
c.u = k
c.z = d
c.p = d
c.r = d
c.w = b
d.u = n
d.y = k
k.v = n
k.s = n
k.y = l
k.u = j
n.v = b
n.w = d
n.x = e
b.q = l
f.y = j
f.r = j
f.p = c
f.v = n
e.x = f
l.o = e
l.y = k
l.w = k
l.t = k
l.x = n
l.v = d
l.p = b
l.u = c
j.y = f
j.r = f
j.p = c
j.v = n
assert c.z.y.u.txt == "j"