class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: E = None
        self.z: A = None
        self.v: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.s: F = None
        self.q: B = None
        self.t: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: F = None
        self.p: A = None
        self.s: F = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: E = None
        self.y: B = None
        self.txt = txt

c = A("c")
k = B("k")
h = C("h")
n = D("n")
b = E("b")
j = F("j")
m = B("m")
a = D("a")
e = E("e")
i = A("i")

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

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

class C:
    def __init__(self, txt: str):
        self.o: D = None
        self.s: F = None
        self.q: B = None
        self.t: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: F = None
        self.p: A = None
        self.s: F = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: E = None
        self.y: B = None
        self.txt = txt

c = A("c")
k = B("k")
h = C("h")
n = D("n")
b = E("b")
j = F("j")
m = B("m")
a = D("a")
e = E("e")
i = A("i")

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