class A:
    def __init__(self, txt: str):
        self.w: E = None
        self.u: D = None
        self.x: G = None
        self.t: B = None
        self.s: G = None
        self.v: E = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.v: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: F = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.v: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: F = None
        self.txt = txt

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

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

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

d.w = h
d.v = h
d.u = e
d.x = a
d.s = a
d.t = j
i.z = e
i.v = f
i.x = l
f.s = l
f.v = a
f.t = d
f.p = e
f.w = e
f.r = i
e.w = i
e.v = a
h.t = l
h.u = l
l.u = j
a.t = l
j.z = e
j.v = f
j.x = l
assert i.x.u.z.v.t.u.z.txt == "e"