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

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

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.y: G = None
        self.u: E = None
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: A = None
        self.o: G = None
        self.txt = txt

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: G = None
        self.y: G = None
        self.z: H = None
        self.w: G = None
        self.u: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.y: G = None
        self.u: E = None
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: A = None
        self.o: G = None
        self.txt = txt

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: G = None
        self.y: G = None
        self.z: H = None
        self.w: G = None
        self.u: F = None
        self.txt = txt

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

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