class A:
    def __init__(self, txt: str):
        self.p: I = None
        self.w: F = None
        self.u: H = None
        self.t: I = None
        self.x: B = None
        self.y: C = None
        self.s: G = None
        self.z: G = None
        self.q: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.y: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.t: A = None
        self.s: I = None
        self.o: D = None
        self.z: B = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.r: C = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.u: B = None
        self.r: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: A = None
        self.r: C = None
        self.s: F = None
        self.o: C = None
        self.x: E = None
        self.q: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.y: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.t: A = None
        self.s: I = None
        self.o: D = None
        self.z: B = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.r: C = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.u: B = None
        self.r: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: A = None
        self.r: C = None
        self.s: F = None
        self.o: C = None
        self.x: E = None
        self.q: F = None
        self.txt = txt

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

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