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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.o: J = None
        self.s: C = None
        self.v: J = None
        self.y: J = None
        self.u: D = None
        self.w: F = None
        self.z: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.u: D = None
        self.r: F = None
        self.p: D = None
        self.o: I = None
        self.x: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: I = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.o: J = None
        self.s: C = None
        self.v: J = None
        self.y: J = None
        self.u: D = None
        self.w: F = None
        self.z: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: E = None
        self.u: D = None
        self.r: F = None
        self.p: D = None
        self.o: I = None
        self.x: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: I = None
        self.txt = txt

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

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