class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.p: C = None
        self.q: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: I = None
        self.v: I = None
        self.w: D = None
        self.q: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: F = None
        self.z: I = None
        self.o: F = None
        self.u: A = None
        self.w: B = None
        self.v: A = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.v: B = None
        self.p: C = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: C = None
        self.q: B = None
        self.s: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

l = A("l")
b = B("b")
k = C("k")
e = D("e")
m = E("m")
j = F("j")
n = G("n")
c = H("c")
h = I("h")

l.t = j
l.p = k
l.q = h
b.u = c
k.r = n
k.q = n
k.t = h
k.v = h
k.w = e
e.y = h
m.r = l
m.u = l
m.v = l
m.p = j
m.o = j
m.z = h
m.w = b
m.t = k
j.z = c
j.v = b
j.p = k
j.u = h
n.u = m
n.t = k
n.q = b
n.s = j
c.r = j
h.u = c
assert m.t.r.t.txt == "
class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.p: C = None
        self.q: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: I = None
        self.v: I = None
        self.w: D = None
        self.q: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: F = None
        self.z: I = None
        self.o: F = None
        self.u: A = None
        self.w: B = None
        self.v: A = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.v: B = None
        self.p: C = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.t: C = None
        self.q: B = None
        self.s: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

l = A("l")
b = B("b")
k = C("k")
e = D("e")
m = E("m")
j = F("j")
n = G("n")
c = H("c")
h = I("h")

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