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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.r: A = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: G = None
        self.t: D = None
        self.q: G = None
        self.r: A = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: F = None
        self.u: H = None
        self.x: H = None
        self.t: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.p: F = None
        self.o: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: C = None
        self.u: H = None
        self.r: B = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: D = None
        self.p: F = None
        self.v: E = None
        self.t: D = None
        self.z: D = None
        self.o: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.r: A = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: G = None
        self.t: D = None
        self.q: G = None
        self.r: A = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: F = None
        self.u: H = None
        self.x: H = None
        self.t: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.p: F = None
        self.o: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: C = None
        self.u: H = None
        self.r: B = None
        self.x: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: D = None
        self.p: F = None
        self.v: E = None
        self.t: D = None
        self.z: D = None
        self.o: D = None
        self.txt = txt

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

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

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

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