class A:
    def __init__(self, txt: str):
        self.z: H = None
        self.r: E = None
        self.y: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: E = None
        self.s: D = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.s: E = None
        self.w: D = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.v: E = None
        self.z: D = None
        self.p: E = None
        self.x: B = None
        self.u: F = None
        self.q: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: E = None
        self.s: D = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.s: E = None
        self.w: D = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.v: E = None
        self.z: D = None
        self.p: E = None
        self.x: B = None
        self.u: F = None
        self.q: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

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

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