class A:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: I = None
        self.s: G = None
        self.z: G = None
        self.v: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.x: C = None
        self.r: E = None
        self.u: G = None
        self.z: J = None
        self.o: J = None
        self.s: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: J = None
        self.u: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: D = None
        self.w: I = None
        self.u: E = None
        self.q: J = None
        self.x: I = None
        self.s: I = None
        self.v: H = None
        self.y: G = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.z: A = None
        self.o: H = None
        self.txt = txt

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

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

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

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

d.w = a
d.y = m
d.s = i
d.z = i
d.v = k
c.p = k
c.y = l
h.r = k
h.y = k
h.s = a
b.v = c
b.x = h
b.r = a
b.u = i
b.z = l
b.o = l
b.s = l
a.r = c
a.x = l
a.u = m
j.p = b
j.w = m
j.x = m
j.s = m
j.u = a
j.r = a
j.q = l
j.v = k
j.y = i
i.s = k
i.o = k
i.z = d
k.s = i
k.u = j
m.v = k
m.q = d
m.x = c
m.w = j
l.u = m
assert l.u.x.y.txt == "
class A:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: I = None
        self.s: G = None
        self.z: G = None
        self.v: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.x: C = None
        self.r: E = None
        self.u: G = None
        self.z: J = None
        self.o: J = None
        self.s: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: J = None
        self.u: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: D = None
        self.w: I = None
        self.u: E = None
        self.q: J = None
        self.x: I = None
        self.s: I = None
        self.v: H = None
        self.y: G = None
        self.r: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.z: A = None
        self.o: H = None
        self.txt = txt

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

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

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

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

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