class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: C = None
        self.x: C = None
        self.z: D = None
        self.s: C = None
        self.txt = txt

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

b = A("b")
h = B("h")
m = C("m")
a = D("a")
j = E("j")
k = F("k")
l = E("l")
c = E("c")
g = F("g")

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

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: C = None
        self.x: C = None
        self.z: D = None
        self.s: C = None
        self.txt = txt

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

b = A("b")
h = B("h")
m = C("m")
a = D("a")
j = E("j")
k = F("k")
l = E("l")
c = E("c")
g = F("g")

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