class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.u: B = None
        self.z: C = None
        self.y: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.o: F = None
        self.v: F = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: F = None
        self.u: B = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.w: E = None
        self.o: G = None
        self.z: A = None
        self.s: A = None
        self.p: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: F = None
        self.w: A = None
        self.y: C = None
        self.z: F = None
        self.r: D = None
        self.v: B = None
        self.q: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: C = None
        self.y: G = None
        self.s: E = None
        self.o: G = None
        self.p: E = None
        self.r: D = None
        self.txt = txt

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

b = A("b")
a = B("a")
d = C("d")
l = D("l")
j = E("j")
m = F("m")
e = G("e")
n = F("n")
c = C("c")
h = G("h")

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

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.o: F = None
        self.v: F = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: B = None
        self.o: F = None
        self.u: B = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.w: E = None
        self.o: G = None
        self.z: A = None
        self.s: A = None
        self.p: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: F = None
        self.w: A = None
        self.y: C = None
        self.z: F = None
        self.r: D = None
        self.v: B = None
        self.q: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: C = None
        self.y: G = None
        self.s: E = None
        self.o: G = None
        self.p: E = None
        self.r: D = None
        self.txt = txt

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

b = A("b")
a = B("a")
d = C("d")
l = D("l")
j = E("j")
m = F("m")
e = G("e")
n = F("n")
c = C("c")
h = G("h")

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