class A:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: C = None
        self.z: F = None
        self.w: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: B = None
        self.t: C = None
        self.w: B = None
        self.z: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: G = None
        self.x: H = None
        self.o: B = None
        self.t: G = None
        self.u: G = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: H = None
        self.z: D = None
        self.r: F = None
        self.x: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: I = None
        self.s: I = None
        self.r: E = None
        self.t: B = None
        self.q: B = None
        self.z: C = None
        self.y: C = None
        self.txt = txt

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

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

f = A("f")
j = B("j")
k = C("k")
b = D("b")
m = E("m")
g = F("g")
n = G("n")
a = H("a")
i = I("i")
e = B("e")

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

class B:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: B = None
        self.t: C = None
        self.w: B = None
        self.z: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: G = None
        self.x: H = None
        self.o: B = None
        self.t: G = None
        self.u: G = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: H = None
        self.z: D = None
        self.r: F = None
        self.x: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: I = None
        self.s: I = None
        self.r: E = None
        self.t: B = None
        self.q: B = None
        self.z: C = None
        self.y: C = None
        self.txt = txt

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

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

f = A("f")
j = B("j")
k = C("k")
b = D("b")
m = E("m")
g = F("g")
n = G("n")
a = H("a")
i = I("i")
e = B("e")

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