class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: D = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.u: H = None
        self.w: C = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: H = None
        self.z: I = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.o: H = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.u: H = None
        self.w: C = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: H = None
        self.z: I = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.o: H = None
        self.txt = txt

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

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

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