class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.p: G = None
        self.r: E = None
        self.u: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.w: F = None
        self.q: G = None
        self.z: G = None
        self.v: B = None
        self.t: B = None
        self.x: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: A = None
        self.txt = txt

k = A("k")
n = B("n")
j = C("j")
g = D("g")
d = E("d")
f = F("f")
a = G("a")
c = D("c")

k.s = f
k.p = a
k.r = d
k.u = j
n.t = a
j.w = f
j.q = a
j.z = a
j.x = a
j.v = n
j.t = n
g.r = n
g.v = n
g.z = j
g.t = j
g.q = j
g.p = a
g.w = f
d.y = a
d.p = f
d.u = f
d.v = f
d.s = k
d.z = j
f.t = c
f.x = a
a.w = c
a.z = k
c.r = n
c.v = n
c.z = j
c.t = j
c.q = j
c.p = a
c.w = f
assert k.r.y.z.txt == "
class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.p: G = None
        self.r: E = None
        self.u: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.w: F = None
        self.q: G = None
        self.z: G = None
        self.v: B = None
        self.t: B = None
        self.x: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: A = None
        self.txt = txt

k = A("k")
n = B("n")
j = C("j")
g = D("g")
d = E("d")
f = F("f")
a = G("a")
c = D("c")

k.s = f
k.p = a
k.r = d
k.u = j
n.t = a
j.w = f
j.q = a
j.z = a
j.x = a
j.v = n
j.t = n
g.r = n
g.v = n
g.z = j
g.t = j
g.q = j
g.p = a
g.w = f
d.y = a
d.p = f
d.u = f
d.v = f
d.s = k
d.z = j
f.t = c
f.x = a
a.w = c
a.z = k
c.r = n
c.v = n
c.z = j
c.t = j
c.q = j
c.p = a
c.w = f
assert k.r.y.z.txt == "k"