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

class B:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: A = None
        self.w: A = None
        self.x: C = None
        self.q: C = None
        self.u: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: F = None
        self.x: A = None
        self.txt = txt

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

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

c = A("c")
g = B("g")
i = C("i")
a = D("a")
l = E("l")
k = F("k")
j = E("j")
m = B("m")

c.x = j
c.r = j
c.y = g
g.s = m
g.z = c
g.w = c
g.x = i
g.q = i
g.u = i
i.z = c
i.x = c
i.y = a
i.t = a
a.z = g
a.o = k
a.x = c
l.q = a
l.t = a
l.s = a
l.v = j
l.x = m
k.w = i
k.v = g
k.x = a
k.z = c
k.y = j
j.q = a
j.t = a
j.s = a
j.v = l
j.x = g
m.s = g
m.z = c
m.w = c
m.x = i
m.q = i
m.u = i
assert g.u.z.r.x.q.t.o.txt == "
class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.r: E = None
        self.y: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: A = None
        self.w: A = None
        self.x: C = None
        self.q: C = None
        self.u: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: F = None
        self.x: A = None
        self.txt = txt

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

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

c = A("c")
g = B("g")
i = C("i")
a = D("a")
l = E("l")
k = F("k")
j = E("j")
m = B("m")

c.x = j
c.r = j
c.y = g
g.s = m
g.z = c
g.w = c
g.x = i
g.q = i
g.u = i
i.z = c
i.x = c
i.y = a
i.t = a
a.z = g
a.o = k
a.x = c
l.q = a
l.t = a
l.s = a
l.v = j
l.x = m
k.w = i
k.v = g
k.x = a
k.z = c
k.y = j
j.q = a
j.t = a
j.s = a
j.v = l
j.x = g
m.s = g
m.z = c
m.w = c
m.x = i
m.q = i
m.u = i
assert g.u.z.r.x.q.t.o.txt == "k"