class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: I = None
        self.v: D = None
        self.z: F = None
        self.s: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.t: G = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: J = None
        self.v: H = None
        self.q: G = None
        self.y: J = None
        self.t: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: J = None
        self.v: B = None
        self.w: J = None
        self.t: B = None
        self.p: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: A = None
        self.z: G = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.z: F = None
        self.r: B = None
        self.q: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.x: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.t: G = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: J = None
        self.v: H = None
        self.q: G = None
        self.y: J = None
        self.t: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: J = None
        self.v: B = None
        self.w: J = None
        self.t: B = None
        self.p: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: A = None
        self.z: G = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.z: F = None
        self.r: B = None
        self.q: G = None
        self.txt = txt

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

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

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