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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: C = None
        self.v: H = None
        self.o: C = None
        self.u: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: C = None
        self.s: J = None
        self.v: D = None
        self.x: G = None
        self.txt = txt

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

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: C = None
        self.v: H = None
        self.o: C = None
        self.u: I = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: F = None
        self.t: C = None
        self.s: J = None
        self.v: D = None
        self.x: G = None
        self.txt = txt

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

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

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

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