class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.q: E = None
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: D = None
        self.t: D = None
        self.x: G = None
        self.u: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.w: A = None
        self.t: F = None
        self.p: H = None
        self.z: F = None
        self.s: I = None
        self.r: H = None
        self.v: F = None
        self.u: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.p: E = None
        self.z: A = None
        self.r: D = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: H = None
        self.o: C = None
        self.y: C = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: D = None
        self.t: D = None
        self.x: G = None
        self.u: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.w: A = None
        self.t: F = None
        self.p: H = None
        self.z: F = None
        self.s: I = None
        self.r: H = None
        self.v: F = None
        self.u: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.p: E = None
        self.z: A = None
        self.r: D = None
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: H = None
        self.o: C = None
        self.y: C = None
        self.q: E = None
        self.s: H = None
        self.txt = txt

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

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

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