class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: F = None
        self.v: D = None
        self.t: C = None
        self.x: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.o: G = None
        self.r: C = None
        self.u: D = None
        self.p: E = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: C = None
        self.w: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: D = None
        self.x: F = None
        self.q: F = None
        self.txt = txt

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

g = A("g")
k = B("k")
i = C("i")
c = D("c")
a = E("a")
e = F("e")
f = G("f")
j = E("j")
b = F("b")
d = C("d")

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

class B:
    def __init__(self, txt: str):
        self.w: F = None
        self.v: D = None
        self.t: C = None
        self.x: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.o: G = None
        self.r: C = None
        self.u: D = None
        self.p: E = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: C = None
        self.w: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: D = None
        self.x: F = None
        self.q: F = None
        self.txt = txt

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

g = A("g")
k = B("k")
i = C("i")
c = D("c")
a = E("a")
e = F("e")
f = G("f")
j = E("j")
b = F("b")
d = C("d")

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