class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.w: J = None
        self.x: H = None
        self.s: J = None
        self.u: J = None
        self.t: H = None
        self.z: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: H = None
        self.q: A = None
        self.o: H = None
        self.s: C = None
        self.x: J = None
        self.p: E = None
        self.w: A = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.s: D = None
        self.v: J = None
        self.o: F = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.t: J = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: H = None
        self.q: A = None
        self.o: H = None
        self.s: C = None
        self.x: J = None
        self.p: E = None
        self.w: A = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.s: D = None
        self.v: J = None
        self.o: F = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.t: J = None
        self.txt = txt

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

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

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

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