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

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

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: C = None
        self.q: E = None
        self.u: D = None
        self.r: B = None
        self.x: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: D = None
        self.r: B = None
        self.o: F = None
        self.u: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: C = None
        self.q: E = None
        self.u: D = None
        self.r: B = None
        self.x: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: D = None
        self.r: B = None
        self.o: F = None
        self.u: D = None
        self.txt = txt

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

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