class A:
    def __init__(self, txt: str):
        self.r: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.z: A = None
        self.y: G = None
        self.u: G = None
        self.v: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.z: G = None
        self.r: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.x: E = None
        self.q: C = None
        self.t: C = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.u: E = None
        self.p: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: D = None
        self.p: E = None
        self.r: B = None
        self.t: G = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.z: A = None
        self.y: G = None
        self.u: G = None
        self.v: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.z: G = None
        self.r: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.x: E = None
        self.q: C = None
        self.t: C = None
        self.s: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: I = None
        self.u: E = None
        self.p: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.v: D = None
        self.p: E = None
        self.r: B = None
        self.t: G = None
        self.txt = txt

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

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