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

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.s: C = None
        self.x: C = None
        self.z: C = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: C = None
        self.y: C = None
        self.o: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.s: C = None
        self.x: C = None
        self.z: C = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: C = None
        self.y: C = None
        self.o: E = None
        self.txt = txt

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

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