class A:
    def __init__(self, txt: str):
        self.r: C = None
        self.o: D = None
        self.s: D = None
        self.v: F = None
        self.z: E = None
        self.w: D = None
        self.txt = txt

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

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

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

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

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

j = A("j")
i = B("i")
m = C("m")
h = D("h")
f = E("f")
d = F("d")
c = E("c")
a = D("a")
l = E("l")
n = B("n")

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

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

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

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

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

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

j = A("j")
i = B("i")
m = C("m")
h = D("h")
f = E("f")
d = F("d")
c = E("c")
a = D("a")
l = E("l")
n = B("n")

j.r = m
j.o = h
j.s = h
j.v = d
j.z = l
j.w = a
i.o = m
i.x = h
i.t = h
i.s = h
m.v = d
m.u = d
h.p = m
h.y = n
h.x = n
f.u = n
f.y = l
d.u = c
d.p = m
c.u = n
c.y = f
a.p = m
a.y = i
a.x = i
l.u = n
l.y = c
n.o = m
n.x = h
n.t = h
n.s = a
assert a.x.t.x.o.u.u.u.txt == "n"