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

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

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: D = None
        self.z: D = None
        self.q: F = None
        self.p: F = None
        self.t: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: D = None
        self.z: D = None
        self.q: F = None
        self.p: F = None
        self.t: B = None
        self.txt = txt

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

c.w = k
c.r = h
c.s = l
i.v = e
i.t = h
i.o = l
h.q = i
m.z = h
m.y = e
m.w = i
m.o = l
e.r = c
e.w = c
j.y = c
j.o = l
j.z = l
j.q = k
j.p = k
j.t = i
n.y = c
n.o = l
n.z = m
n.q = j
n.p = k
n.t = i
l.z = h
l.y = e
l.w = i
l.o = m
k.y = c
k.o = m
k.z = l
k.q = j
k.p = n
k.t = i
assert e.w.r.q.t.q.txt == "i"