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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: G = None
        self.o: A = None
        self.u: C = None
        self.x: E = None
        self.q: C = None
        self.y: F = None
        self.p: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: F = None
        self.u: A = None
        self.q: A = None
        self.y: A = None
        self.w: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.y: A = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: D = None
        self.u: D = None
        self.y: F = None
        self.t: D = None
        self.w: B = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.t: A = None
        self.u: H = None
        self.w: B = None
        self.s: H = None
        self.p: G = None
        self.q: A = None
        self.o: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: A = None
        self.v: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: G = None
        self.o: A = None
        self.u: C = None
        self.x: E = None
        self.q: C = None
        self.y: F = None
        self.p: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: F = None
        self.u: A = None
        self.q: A = None
        self.y: A = None
        self.w: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.y: A = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: B = None
        self.z: D = None
        self.u: D = None
        self.y: F = None
        self.t: D = None
        self.w: B = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: B = None
        self.t: A = None
        self.u: H = None
        self.w: B = None
        self.s: H = None
        self.p: G = None
        self.q: A = None
        self.o: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.y: A = None
        self.v: F = None
        self.txt = txt

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

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

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