class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: E = None
        self.o: G = None
        self.w: C = None
        self.q: B = None
        self.y: E = None
        self.t: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.p: D = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.p: G = None
        self.t: F = None
        self.z: E = None
        self.o: D = None
        self.w: B = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: G = None
        self.z: E = None
        self.r: G = None
        self.q: A = None
        self.u: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.p: D = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.p: G = None
        self.t: F = None
        self.z: E = None
        self.o: D = None
        self.w: B = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: G = None
        self.z: E = None
        self.r: G = None
        self.q: A = None
        self.u: C = None
        self.txt = txt

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

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

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