class A:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: G = None
        self.w: H = None
        self.o: G = None
        self.q: C = None
        self.z: D = None
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.o: A = None
        self.p: I = None
        self.w: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: C = None
        self.z: J = None
        self.q: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: C = None
        self.p: J = None
        self.x: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.q: I = None
        self.u: I = None
        self.y: C = None
        self.w: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: C = None
        self.w: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: J = None
        self.z: A = None
        self.s: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.o: A = None
        self.p: I = None
        self.w: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: C = None
        self.z: J = None
        self.q: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: C = None
        self.p: J = None
        self.x: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: J = None
        self.q: I = None
        self.u: I = None
        self.y: C = None
        self.w: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: C = None
        self.w: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: J = None
        self.z: A = None
        self.s: D = None
        self.txt = txt

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

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

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