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

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.z: D = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: G = None
        self.v: E = None
        self.u: E = None
        self.y: B = None
        self.z: I = None
        self.w: G = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.z: C = None
        self.v: C = None
        self.u: G = None
        self.r: H = None
        self.p: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.q: F = None
        self.z: D = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: G = None
        self.v: E = None
        self.u: E = None
        self.y: B = None
        self.z: I = None
        self.w: G = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.z: C = None
        self.v: C = None
        self.u: G = None
        self.r: H = None
        self.p: A = None
        self.txt = txt

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

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