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

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.o: A = None
        self.v: D = None
        self.r: G = None
        self.y: E = None
        self.q: E = None
        self.u: H = None
        self.x: D = None
        self.z: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: J = None
        self.x: A = None
        self.v: H = None
        self.q: J = None
        self.z: G = None
        self.t: B = None
        self.s: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.z: A = None
        self.s: J = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: C = None
        self.z: G = None
        self.v: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: B = None
        self.x: H = None
        self.w: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.o: A = None
        self.v: D = None
        self.r: G = None
        self.y: E = None
        self.q: E = None
        self.u: H = None
        self.x: D = None
        self.z: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: J = None
        self.x: A = None
        self.v: H = None
        self.q: J = None
        self.z: G = None
        self.t: B = None
        self.s: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: A = None
        self.z: A = None
        self.s: J = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: C = None
        self.z: G = None
        self.v: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: B = None
        self.x: H = None
        self.w: C = None
        self.txt = txt

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

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