class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: G = None
        self.w: C = None
        self.r: B = None
        self.v: G = None
        self.u: C = None
        self.s: E = None
        self.t: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: H = None
        self.y: D = None
        self.r: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: B = None
        self.y: G = None
        self.p: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: G = None
        self.x: G = None
        self.o: H = None
        self.v: E = None
        self.q: E = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: H = None
        self.u: D = None
        self.z: F = None
        self.v: B = None
        self.r: F = None
        self.w: C = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.x: C = None
        self.t: C = None
        self.q: A = None
        self.p: A = None
        self.o: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: H = None
        self.y: D = None
        self.r: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: B = None
        self.y: G = None
        self.p: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: G = None
        self.x: G = None
        self.o: H = None
        self.v: E = None
        self.q: E = None
        self.p: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: H = None
        self.u: D = None
        self.z: F = None
        self.v: B = None
        self.r: F = None
        self.w: C = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.x: C = None
        self.t: C = None
        self.q: A = None
        self.p: A = None
        self.o: G = None
        self.txt = txt

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

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