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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.o: D = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: E = None
        self.t: F = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.o: D = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: E = None
        self.t: F = None
        self.txt = txt

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

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