class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.s: C = None
        self.o: A = None
        self.p: G = None
        self.v: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: E = None
        self.p: D = None
        self.o: E = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: A = None
        self.z: A = None
        self.o: C = None
        self.v: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: A = None
        self.x: E = None
        self.s: C = None
        self.o: C = None
        self.txt = txt

c = A("c")
k = B("k")
i = C("i")
a = D("a")
h = E("h")
b = F("b")
j = G("j")
l = A("l")

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

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

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: E = None
        self.p: D = None
        self.o: E = None
        self.t: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: A = None
        self.z: A = None
        self.o: C = None
        self.v: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: A = None
        self.x: E = None
        self.s: C = None
        self.o: C = None
        self.txt = txt

c = A("c")
k = B("k")
i = C("i")
a = D("a")
h = E("h")
b = F("b")
j = G("j")
l = A("l")

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