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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: B = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.p: D = None
        self.r: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.r: B = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: E = None
        self.txt = txt

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

l = A("l")
j = B("j")
n = C("n")
b = D("b")
a = E("a")
g = F("g")
h = G("h")
e = G("e")
k = B("k")

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: B = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.p: D = None
        self.r: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.r: B = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: E = None
        self.txt = txt

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

l = A("l")
j = B("j")
n = C("n")
b = D("b")
a = E("a")
g = F("g")
h = G("h")
e = G("e")
k = B("k")

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