class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: I = None
        self.p: I = None
        self.y: H = None
        self.x: D = None
        self.o: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: D = None
        self.z: B = None
        self.s: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.z: I = None
        self.o: G = None
        self.u: E = None
        self.p: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: H = None
        self.s: H = None
        self.y: D = None
        self.z: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.o: D = None
        self.z: B = None
        self.s: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.z: I = None
        self.o: G = None
        self.u: E = None
        self.p: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: H = None
        self.s: H = None
        self.y: D = None
        self.z: C = None
        self.txt = txt

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

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