class A:
    def __init__(self, txt: str):
        self.t: C = None
        self.p: C = None
        self.y: B = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.q: A = None
        self.o: D = None
        self.v: F = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: C = None
        self.s: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.y: B = None
        self.w: B = None
        self.txt = txt

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

e = A("e")
n = B("n")
j = C("j")
c = D("c")
d = E("d")
k = F("k")
a = G("a")
f = G("f")
h = D("h")
l = C("l")

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

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

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

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.q: A = None
        self.o: D = None
        self.v: F = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: C = None
        self.s: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.y: B = None
        self.w: B = None
        self.txt = txt

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

e = A("e")
n = B("n")
j = C("j")
c = D("c")
d = E("d")
k = F("k")
a = G("a")
f = G("f")
h = D("h")
l = C("l")

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