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

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.o: C = None
        self.v: C = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: J = None
        self.u: J = None
        self.v: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: B = None
        self.v: D = None
        self.r: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: I = None
        self.q: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.o: C = None
        self.v: C = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: J = None
        self.u: J = None
        self.v: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: B = None
        self.v: D = None
        self.r: H = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: I = None
        self.q: A = None
        self.txt = txt

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

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