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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.u: A = None
        self.t: G = None
        self.p: H = None
        self.q: H = None
        self.s: J = None
        self.x: F = None
        self.r: C = None
        self.w: D = None
        self.z: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.y: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.s: E = None
        self.z: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: C = None
        self.t: A = None
        self.u: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: G = None
        self.r: F = None
        self.v: G = None
        self.u: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.u: A = None
        self.t: G = None
        self.p: H = None
        self.q: H = None
        self.s: J = None
        self.x: F = None
        self.r: C = None
        self.w: D = None
        self.z: H = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.y: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.s: E = None
        self.z: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: C = None
        self.t: A = None
        self.u: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: G = None
        self.r: F = None
        self.v: G = None
        self.u: E = None
        self.txt = txt

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

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

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