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

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: H = None
        self.o: I = None
        self.t: A = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: I = None
        self.p: B = None
        self.o: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.u: B = None
        self.y: A = None
        self.q: B = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.q: H = None
        self.y: B = None
        self.x: C = None
        self.t: A = None
        self.z: D = None
        self.v: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.t: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.s: D = None
        self.z: C = None
        self.p: E = None
        self.y: B = None
        self.v: C = None
        self.t: H = None
        self.x: A = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.s: H = None
        self.o: I = None
        self.t: A = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: I = None
        self.p: B = None
        self.o: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.u: B = None
        self.y: A = None
        self.q: B = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.q: H = None
        self.y: B = None
        self.x: C = None
        self.t: A = None
        self.z: D = None
        self.v: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.t: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.s: D = None
        self.z: C = None
        self.p: E = None
        self.y: B = None
        self.v: C = None
        self.t: H = None
        self.x: A = None
        self.txt = txt

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

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

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