class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.u: G = None
        self.p: B = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: D = None
        self.u: G = None
        self.w: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: G = None
        self.o: C = None
        self.u: E = None
        self.r: I = None
        self.s: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.p: E = None
        self.y: E = None
        self.w: F = None
        self.q: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.q: F = None
        self.v: G = None
        self.t: D = None
        self.w: F = None
        self.txt = txt

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

d.x = f
l.p = c
k.w = f
k.t = j
k.x = a
j.w = k
j.u = c
j.p = l
j.z = a
a.q = g
a.w = g
a.o = j
a.u = c
f.v = j
f.y = c
f.o = k
f.u = a
f.s = a
f.r = e
c.o = g
g.u = f
g.w = f
g.p = a
g.y = a
g.q = a
e.p = j
e.t = j
e.q = f
e.w = f
e.v = c
assert d.x.y.o.y.u.txt == "
class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.u: G = None
        self.p: B = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: D = None
        self.u: G = None
        self.w: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: G = None
        self.o: C = None
        self.u: E = None
        self.r: I = None
        self.s: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.p: E = None
        self.y: E = None
        self.w: F = None
        self.q: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.q: F = None
        self.v: G = None
        self.t: D = None
        self.w: F = None
        self.txt = txt

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

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