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

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: B = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.z: I = None
        self.y: A = None
        self.r: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: C = None
        self.v: H = None
        self.s: F = None
        self.p: H = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.r: B = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.z: I = None
        self.y: A = None
        self.r: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: C = None
        self.v: H = None
        self.s: F = None
        self.p: H = None
        self.txt = txt

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

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