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

class B:
    def __init__(self, txt: str):
        self.s: A = None
        self.x: I = None
        self.t: I = None
        self.q: I = None
        self.v: A = None
        self.w: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.o: H = None
        self.p: G = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: I = None
        self.s: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: C = None
        self.w: H = None
        self.t: D = None
        self.r: D = None
        self.txt = txt

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

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

d = A("d")
g = B("g")
k = C("k")
n = D("n")
f = E("f")
a = F("a")
j = G("j")
l = H("l")
i = I("i")

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

class B:
    def __init__(self, txt: str):
        self.s: A = None
        self.x: I = None
        self.t: I = None
        self.q: I = None
        self.v: A = None
        self.w: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.o: H = None
        self.p: G = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: I = None
        self.s: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: C = None
        self.w: H = None
        self.t: D = None
        self.r: D = None
        self.txt = txt

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

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

d = A("d")
g = B("g")
k = C("k")
n = D("n")
f = E("f")
a = F("a")
j = G("j")
l = H("l")
i = I("i")

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