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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.u: I = None
        self.t: F = None
        self.r: F = None
        self.w: G = None
        self.z: B = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.v: E = None
        self.p: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.s: G = None
        self.o: E = None
        self.q: B = None
        self.u: I = None
        self.v: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: A = None
        self.s: G = None
        self.p: C = None
        self.t: E = None
        self.u: D = None
        self.q: I = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.x: E = None
        self.p: B = None
        self.s: H = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.u: I = None
        self.t: F = None
        self.r: F = None
        self.w: G = None
        self.z: B = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: H = None
        self.v: E = None
        self.p: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.s: G = None
        self.o: E = None
        self.q: B = None
        self.u: I = None
        self.v: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: A = None
        self.s: G = None
        self.p: C = None
        self.t: E = None
        self.u: D = None
        self.q: I = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: B = None
        self.x: E = None
        self.p: B = None
        self.s: H = None
        self.txt = txt

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

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