class A:
    def __init__(self, txt: str):
        self.r: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: B = None
        self.x: F = None
        self.q: I = None
        self.v: D = None
        self.t: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: E = None
        self.o: B = None
        self.p: G = None
        self.z: I = None
        self.q: C = None
        self.w: D = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: A = None
        self.v: D = None
        self.p: I = None
        self.x: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: B = None
        self.x: F = None
        self.q: I = None
        self.v: D = None
        self.t: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: E = None
        self.o: B = None
        self.p: G = None
        self.z: I = None
        self.q: C = None
        self.w: D = None
        self.u: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: A = None
        self.v: D = None
        self.p: I = None
        self.x: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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

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