class A:
    def __init__(self, txt: str):
        self.y: G = None
        self.v: A = None
        self.w: F = None
        self.s: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.q: A = None
        self.t: E = None
        self.u: D = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: E = None
        self.y: E = None
        self.v: B = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: D = None
        self.r: G = None
        self.q: F = None
        self.v: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: C = None
        self.v: G = None
        self.r: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: C = None
        self.q: A = None
        self.t: E = None
        self.u: D = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: E = None
        self.y: E = None
        self.v: B = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: D = None
        self.r: G = None
        self.q: F = None
        self.v: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: C = None
        self.v: G = None
        self.r: D = None
        self.txt = txt

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

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

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