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

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

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: F = None
        self.r: A = None
        self.y: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: H = None
        self.x: D = None
        self.r: H = None
        self.q: E = None
        self.u: B = None
        self.p: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.x: E = None
        self.w: G = None
        self.t: F = None
        self.z: E = None
        self.v: C = None
        self.y: G = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: D = None
        self.x: E = None
        self.u: C = None
        self.v: A = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.x: B = None
        self.s: F = None
        self.r: A = None
        self.y: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: H = None
        self.x: D = None
        self.r: H = None
        self.q: E = None
        self.u: B = None
        self.p: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.x: E = None
        self.w: G = None
        self.t: F = None
        self.z: E = None
        self.v: C = None
        self.y: G = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: D = None
        self.x: E = None
        self.u: C = None
        self.v: A = None
        self.txt = txt

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

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