class A:
    def __init__(self, txt: str):
        self.x: C = None
        self.t: H = None
        self.v: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: H = None
        self.w: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.p: H = None
        self.z: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: H = None
        self.w: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.p: H = None
        self.z: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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