class A:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: B = None
        self.o: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: E = None
        self.u: H = None
        self.p: H = None
        self.w: I = None
        self.z: A = None
        self.q: E = None
        self.s: E = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: G = None
        self.q: I = None
        self.r: A = None
        self.u: H = None
        self.o: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: A = None
        self.w: E = None
        self.s: I = None
        self.txt = txt

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

b = A("b")
n = B("n")
a = C("a")
f = D("f")
h = E("h")
l = F("l")
m = G("m")
e = H("e")
i = I("i")
d = B("d")

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

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

class C:
    def __init__(self, txt: str):
        self.r: I = None
        self.o: E = None
        self.u: H = None
        self.p: H = None
        self.w: I = None
        self.z: A = None
        self.q: E = None
        self.s: E = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: G = None
        self.q: I = None
        self.r: A = None
        self.u: H = None
        self.o: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: A = None
        self.w: E = None
        self.s: I = None
        self.txt = txt

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

b = A("b")
n = B("n")
a = C("a")
f = D("f")
h = E("h")
l = F("l")
m = G("m")
e = H("e")
i = I("i")
d = B("d")

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