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

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: F = None
        self.u: B = None
        self.v: A = None
        self.o: H = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.s: F = None
        self.t: F = None
        self.p: J = None
        self.q: C = None
        self.x: F = None
        self.v: G = None
        self.r: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.v: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: D = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.x: F = None
        self.u: B = None
        self.v: A = None
        self.o: H = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.s: F = None
        self.t: F = None
        self.p: J = None
        self.q: C = None
        self.x: F = None
        self.v: G = None
        self.r: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.v: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: D = None
        self.txt = txt

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

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

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

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