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

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.t: F = None
        self.o: F = None
        self.txt = txt

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

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

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

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

e = A("e")
l = B("l")
g = C("g")
a = D("a")
d = E("d")
h = F("h")
m = D("m")
n = F("n")
c = F("c")

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

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.t: F = None
        self.o: F = None
        self.txt = txt

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

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

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

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

e = A("e")
l = B("l")
g = C("g")
a = D("a")
d = E("d")
h = F("h")
m = D("m")
n = F("n")
c = F("c")

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