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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: H = None
        self.q: I = None
        self.t: B = None
        self.x: B = None
        self.y: H = None
        self.o: J = None
        self.v: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: I = None
        self.z: A = None
        self.q: B = None
        self.o: B = None
        self.t: F = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: C = None
        self.v: H = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: H = None
        self.q: I = None
        self.t: B = None
        self.x: B = None
        self.y: H = None
        self.o: J = None
        self.v: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: I = None
        self.z: A = None
        self.q: B = None
        self.o: B = None
        self.t: F = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.t: C = None
        self.u: C = None
        self.v: H = None
        self.txt = txt

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

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

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