class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.v: C = None
        self.u: E = None
        self.z: C = None
        self.r: D = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: E = None
        self.t: G = None
        self.s: E = None
        self.z: B = None
        self.q: A = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: G = None
        self.x: B = None
        self.o: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.y: A = None
        self.q: D = None
        self.r: D = None
        self.txt = txt

k = A("k")
h = B("h")
j = C("j")
g = D("g")
f = E("f")
l = F("l")
b = G("b")
e = C("e")

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: E = None
        self.t: G = None
        self.s: E = None
        self.z: B = None
        self.q: A = None
        self.w: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: G = None
        self.x: B = None
        self.o: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.y: A = None
        self.q: D = None
        self.r: D = None
        self.txt = txt

k = A("k")
h = B("h")
j = C("j")
g = D("g")
f = E("f")
l = F("l")
b = G("b")
e = C("e")

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