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

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.o: A = None
        self.q: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.q: A = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: B = None
        self.t: A = None
        self.u: C = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.o: A = None
        self.q: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: H = None
        self.t: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.q: A = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: B = None
        self.t: A = None
        self.u: C = None
        self.txt = txt

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

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

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