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

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: D = None
        self.s: E = None
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: A = None
        self.w: E = None
        self.x: B = None
        self.y: A = None
        self.q: A = None
        self.v: B = None
        self.p: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: H = None
        self.y: H = None
        self.v: G = None
        self.x: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: G = None
        self.x: C = None
        self.w: D = None
        self.r: A = None
        self.t: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.s: D = None
        self.y: C = None
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.q: F = None
        self.p: D = None
        self.r: D = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: D = None
        self.s: E = None
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.r: A = None
        self.w: E = None
        self.x: B = None
        self.y: A = None
        self.q: A = None
        self.v: B = None
        self.p: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.s: H = None
        self.y: H = None
        self.v: G = None
        self.x: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: G = None
        self.x: C = None
        self.w: D = None
        self.r: A = None
        self.t: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: B = None
        self.s: D = None
        self.y: C = None
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.q: F = None
        self.p: D = None
        self.r: D = None
        self.txt = txt

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

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

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