class A:
    def __init__(self, txt: str):
        self.r: C = None
        self.y: D = None
        self.o: C = None
        self.v: D = None
        self.s: J = None
        self.u: C = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: H = None
        self.r: A = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: G = None
        self.o: H = None
        self.u: D = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.z: A = None
        self.p: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.w: A = None
        self.x: G = None
        self.s: G = None
        self.o: B = None
        self.t: J = None
        self.q: B = None
        self.z: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: E = None
        self.y: B = None
        self.o: H = None
        self.s: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: I = None
        self.p: G = None
        self.z: J = None
        self.o: C = None
        self.v: F = None
        self.q: B = None
        self.r: G = None
        self.t: J = None
        self.w: D = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: H = None
        self.r: A = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: G = None
        self.o: H = None
        self.u: D = None
        self.q: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: G = None
        self.z: A = None
        self.p: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.w: A = None
        self.x: G = None
        self.s: G = None
        self.o: B = None
        self.t: J = None
        self.q: B = None
        self.z: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: E = None
        self.y: B = None
        self.o: H = None
        self.s: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: I = None
        self.p: G = None
        self.z: J = None
        self.o: C = None
        self.v: F = None
        self.q: B = None
        self.r: G = None
        self.t: J = None
        self.w: D = None
        self.txt = txt

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

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

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

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