class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.x: C = None
        self.s: D = None
        self.v: F = None
        self.w: B = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: B = None
        self.q: C = None
        self.t: A = None
        self.w: A = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: B = None
        self.q: C = None
        self.t: A = None
        self.w: A = None
        self.txt = txt

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

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