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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.t: F = None
        self.s: J = None
        self.r: C = None
        self.u: E = None
        self.z: E = None
        self.q: J = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.q: B = None
        self.v: H = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: G = None
        self.x: H = None
        self.v: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: I = None
        self.v: B = None
        self.p: E = None
        self.w: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: J = None
        self.w: C = None
        self.x: G = None
        self.p: E = None
        self.z: F = None
        self.y: A = None
        self.r: G = None
        self.s: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: D = None
        self.u: F = None
        self.x: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.t: F = None
        self.s: J = None
        self.r: C = None
        self.u: E = None
        self.z: E = None
        self.q: J = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.q: B = None
        self.v: H = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: F = None
        self.p: G = None
        self.x: H = None
        self.v: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: I = None
        self.v: B = None
        self.p: E = None
        self.w: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: J = None
        self.w: C = None
        self.x: G = None
        self.p: E = None
        self.z: F = None
        self.y: A = None
        self.r: G = None
        self.s: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: D = None
        self.u: F = None
        self.x: G = None
        self.txt = txt

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

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