class A:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: D = None
        self.x: H = None
        self.y: G = None
        self.v: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: A = None
        self.t: C = None
        self.q: C = None
        self.p: H = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.p: A = None
        self.t: D = None
        self.x: C = None
        self.r: C = None
        self.s: E = None
        self.y: D = None
        self.txt = txt

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

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

f.u = b
a.w = e
a.z = i
a.x = h
g.z = h
g.v = h
g.q = i
g.x = b
g.y = n
i.y = e
i.t = e
i.o = h
i.r = g
e.s = h
e.v = f
e.t = g
e.q = g
e.p = b
h.r = f
h.x = f
h.o = i
h.q = g
n.y = i
n.w = i
n.v = i
n.r = g
n.z = b
b.v = e
b.s = e
b.o = f
b.p = f
b.t = i
b.y = i
b.x = g
b.r = g
l.s = b
l.o = n
assert e.v.u.s.t.q.txt == "
class A:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: F = None
        self.q: D = None
        self.x: H = None
        self.y: G = None
        self.v: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: A = None
        self.t: C = None
        self.q: C = None
        self.p: H = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.o: A = None
        self.p: A = None
        self.t: D = None
        self.x: C = None
        self.r: C = None
        self.s: E = None
        self.y: D = None
        self.txt = txt

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

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

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