class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.x: G = None
        self.r: I = None
        self.s: G = None
        self.t: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.w: E = None
        self.y: I = None
        self.s: C = None
        self.z: A = None
        self.t: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.v: I = None
        self.s: E = None
        self.u: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.t: B = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: A = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.w: E = None
        self.y: I = None
        self.s: C = None
        self.z: A = None
        self.t: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.v: I = None
        self.s: E = None
        self.u: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.t: B = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: A = None
        self.txt = txt

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

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

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