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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.w: D = None
        self.r: G = None
        self.z: G = None
        self.s: C = None
        self.u: D = None
        self.t: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.q: G = None
        self.y: C = None
        self.v: C = None
        self.s: G = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: G = None
        self.p: B = None
        self.txt = txt

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

e = A("e")
l = B("l")
g = C("g")
d = D("d")
j = E("j")
i = F("i")
a = G("a")
n = D("n")
k = E("k")

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.w: D = None
        self.r: G = None
        self.z: G = None
        self.s: C = None
        self.u: D = None
        self.t: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.q: G = None
        self.y: C = None
        self.v: C = None
        self.s: G = None
        self.u: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: G = None
        self.p: B = None
        self.txt = txt

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

e = A("e")
l = B("l")
g = C("g")
d = D("d")
j = E("j")
i = F("i")
a = G("a")
n = D("n")
k = E("k")

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