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

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

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

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: D = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: B = None
        self.v: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: F = None
        self.w: A = None
        self.p: I = None
        self.t: B = None
        self.q: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.u: A = None
        self.t: E = None
        self.o: F = None
        self.w: I = None
        self.v: F = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: D = None
        self.v: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: B = None
        self.v: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: F = None
        self.w: A = None
        self.p: I = None
        self.t: B = None
        self.q: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.u: A = None
        self.t: E = None
        self.o: F = None
        self.w: I = None
        self.v: F = None
        self.txt = txt

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

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

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