class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: D = None
        self.u: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: I = None
        self.x: I = None
        self.y: E = None
        self.o: B = None
        self.t: I = None
        self.z: I = None
        self.p: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.r: D = None
        self.o: E = None
        self.v: A = None
        self.t: H = None
        self.txt = txt

l = A("l")
d = B("d")
h = C("h")
j = D("j")
i = E("i")
k = F("k")
a = G("a")
m = H("m")
c = I("c")

l.x = d
d.t = k
d.y = l
d.u = j
d.r = j
d.w = h
d.p = h
d.v = i
h.z = m
j.v = m
j.y = m
j.r = i
j.t = k
j.p = l
j.u = l
j.x = d
j.w = c
i.y = a
i.w = j
i.u = m
k.u = c
k.x = c
k.t = c
k.z = c
k.y = i
k.o = d
k.p = h
a.p = m
a.r = k
a.v = k
a.o = d
a.u = l
a.q = c
a.t = h
m.w = l
m.s = d
c.w = k
c.r = j
c.o = i
c.v = l
c.t = m
assert d.t.y.u.s.p.z.w.x.txt == "
class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: D = None
        self.u: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: I = None
        self.x: I = None
        self.y: E = None
        self.o: B = None
        self.t: I = None
        self.z: I = None
        self.p: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.r: D = None
        self.o: E = None
        self.v: A = None
        self.t: H = None
        self.txt = txt

l = A("l")
d = B("d")
h = C("h")
j = D("j")
i = E("i")
k = F("k")
a = G("a")
m = H("m")
c = I("c")

l.x = d
d.t = k
d.y = l
d.u = j
d.r = j
d.w = h
d.p = h
d.v = i
h.z = m
j.v = m
j.y = m
j.r = i
j.t = k
j.p = l
j.u = l
j.x = d
j.w = c
i.y = a
i.w = j
i.u = m
k.u = c
k.x = c
k.t = c
k.z = c
k.y = i
k.o = d
k.p = h
a.p = m
a.r = k
a.v = k
a.o = d
a.u = l
a.q = c
a.t = h
m.w = l
m.s = d
c.w = k
c.r = j
c.o = i
c.v = l
c.t = m
assert d.t.y.u.s.p.z.w.x.txt == "d"