class A:
    def __init__(self, txt: str):
        self.t: I = None
        self.z: E = None
        self.w: E = None
        self.s: C = None
        self.r: J = None
        self.x: D = None
        self.p: D = None
        self.o: C = None
        self.u: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: I = None
        self.r: E = None
        self.s: C = None
        self.v: G = None
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.w: E = None
        self.q: D = None
        self.u: J = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: J = None
        self.r: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: I = None
        self.w: I = None
        self.q: B = None
        self.p: C = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: C = None
        self.r: E = None
        self.p: E = None
        self.x: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: J = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.z: F = None
        self.o: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: I = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: I = None
        self.r: E = None
        self.s: C = None
        self.v: G = None
        self.w: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.w: E = None
        self.q: D = None
        self.u: J = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: J = None
        self.r: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: I = None
        self.w: I = None
        self.q: B = None
        self.p: C = None
        self.y: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: C = None
        self.r: E = None
        self.p: E = None
        self.x: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: J = None
        self.o: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.z: F = None
        self.o: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: I = None
        self.txt = txt

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

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