class A:
    def __init__(self, txt: str):
        self.u: H = None
        self.q: H = None
        self.x: E = None
        self.t: H = None
        self.s: D = None
        self.y: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: H = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.u: B = None
        self.q: G = None
        self.r: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: H = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.u: B = None
        self.q: G = None
        self.r: D = None
        self.txt = txt

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

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

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