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

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

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

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: F = None
        self.s: B = None
        self.t: F = None
        self.q: F = None
        self.p: C = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: F = None
        self.s: B = None
        self.t: F = None
        self.q: F = None
        self.p: C = None
        self.txt = txt

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

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

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

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