class A:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: H = None
        self.s: I = None
        self.y: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.z: B = None
        self.w: I = None
        self.r: A = None
        self.u: D = None
        self.t: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.z: I = None
        self.r: I = None
        self.p: F = None
        self.q: D = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.w: E = None
        self.r: I = None
        self.u: B = None
        self.p: A = None
        self.q: A = None
        self.y: E = None
        self.s: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: C = None
        self.v: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.z: B = None
        self.w: I = None
        self.r: A = None
        self.u: D = None
        self.t: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: F = None
        self.z: I = None
        self.r: I = None
        self.p: F = None
        self.q: D = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.w: E = None
        self.r: I = None
        self.u: B = None
        self.p: A = None
        self.q: A = None
        self.y: E = None
        self.s: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: C = None
        self.txt = txt

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

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