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

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

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

class D:
    def __init__(self, txt: str):
        self.q: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: C = None
        self.t: J = None
        self.w: J = None
        self.s: F = None
        self.v: F = None
        self.o: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: E = None
        self.s: D = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: E = None
        self.z: B = None
        self.t: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: C = None
        self.v: E = None
        self.w: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

l = A("l")
n = B("n")
i = C("i")
j = D("j")
a = E("a")
e = F("e")
b = G("b")
d = H("d")
k = I("k")
m = J("m")

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

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

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

class D:
    def __init__(self, txt: str):
        self.q: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: C = None
        self.t: J = None
        self.w: J = None
        self.s: F = None
        self.v: F = None
        self.o: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: E = None
        self.s: D = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.q: E = None
        self.z: B = None
        self.t: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: C = None
        self.v: E = None
        self.w: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

l = A("l")
n = B("n")
i = C("i")
j = D("j")
a = E("a")
e = F("e")
b = G("b")
d = H("d")
k = I("k")
m = J("m")

l.q = k
l.u = k
n.w = e
n.z = e
n.q = l
n.x = l
n.t = m
n.v = b
n.r = b
n.u = k
i.u = n
i.r = n
i.t = a
j.q = m
a.z = e
a.s = e
a.v = e
a.x = i
a.t = m
a.w = m
a.o = d
e.u = d
e.r = d
e.p = a
e.s = j
b.x = e
b.u = l
d.s = i
d.t = i
d.q = a
d.z = n
k.q = i
k.v = a
k.w = a
m.s = j
assert i.t.o.q.x.t.txt == "a"