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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: D = None
        self.r: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.z: H = None
        self.txt = txt

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

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: D = None
        self.r: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.z: H = None
        self.txt = txt

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

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

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

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

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

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

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