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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: J = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.s: B = None
        self.z: H = None
        self.v: D = None
        self.txt = txt

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: E = None
        self.y: B = None
        self.z: E = None
        self.s: A = None
        self.x: A = None
        self.v: E = None
        self.r: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: F = None
        self.o: E = None
        self.txt = txt

i = A("i")
k = B("k")
j = C("j")
h = D("h")
n = E("n")
g = F("g")
d = G("d")
m = H("m")
f = I("f")
b = J("b")

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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.w: J = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.s: B = None
        self.z: H = None
        self.v: D = None
        self.txt = txt

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.t: H = None
        self.p: E = None
        self.y: B = None
        self.z: E = None
        self.s: A = None
        self.x: A = None
        self.v: E = None
        self.r: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: F = None
        self.o: E = None
        self.txt = txt

i = A("i")
k = B("k")
j = C("j")
h = D("h")
n = E("n")
g = F("g")
d = G("d")
m = H("m")
f = I("f")
b = J("b")

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