class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.t: J = None
        self.u: D = None
        self.y: G = None
        self.z: H = None
        self.r: D = None
        self.v: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.r: F = None
        self.v: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: B = None
        self.t: B = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.s: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.r: J = None
        self.p: I = None
        self.y: I = None
        self.u: C = None
        self.w: D = None
        self.o: G = None
        self.z: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: E = None
        self.r: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: I = None
        self.v: I = None
        self.u: F = None
        self.q: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: F = None
        self.v: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.r: F = None
        self.v: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.w: B = None
        self.t: B = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: B = None
        self.s: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.r: J = None
        self.p: I = None
        self.y: I = None
        self.u: C = None
        self.w: D = None
        self.o: G = None
        self.z: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: E = None
        self.r: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: I = None
        self.v: I = None
        self.u: F = None
        self.q: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: F = None
        self.v: E = None
        self.txt = txt

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

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