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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: D = None
        self.q: C = None
        self.z: E = None
        self.t: C = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: D = None
        self.q: C = None
        self.z: E = None
        self.t: C = None
        self.txt = txt

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

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

j.v = f
j.u = c
j.z = c
j.y = e
i.p = j
i.s = f
e.w = i
e.v = l
e.s = l
f.q = c
f.x = j
m.s = i
m.v = f
m.q = e
m.t = e
m.z = c
l.t = f
l.q = j
l.s = j
h.s = i
h.v = f
h.q = e
h.t = e
h.z = c
c.s = i
c.v = f
c.q = e
c.t = e
c.z = m
assert f.x.u.q.w.p.y.w.txt == "i"