class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.o: E = None
        self.w: D = None
        self.p: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.r: G = None
        self.w: F = None
        self.q: G = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.y: G = None
        self.t: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.s: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.r: G = None
        self.w: F = None
        self.q: G = None
        self.t: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.y: G = None
        self.t: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.s: B = None
        self.txt = txt

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

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