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

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.v: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.s: E = None
        self.z: F = None
        self.q: G = None
        self.w: A = None
        self.y: E = None
        self.txt = txt

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

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

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

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

i = A("i")
e = B("e")
c = C("c")
n = D("n")
a = E("a")
m = F("m")
g = G("g")
k = G("k")

i.s = m
e.t = n
e.v = m
e.r = i
c.x = i
c.w = i
c.s = a
c.y = a
c.z = m
c.q = k
n.t = m
n.v = e
a.r = k
a.u = i
a.s = i
a.w = i
a.p = m
m.z = a
m.r = i
m.y = i
m.s = i
m.u = c
m.v = g
g.v = a
g.x = n
g.u = e
g.y = e
g.r = c
g.s = c
g.o = c
k.v = a
k.x = n
k.u = e
k.y = e
k.r = c
k.s = c
k.o = c
assert a.p.u.z.z.txt == "
class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.v: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.s: E = None
        self.z: F = None
        self.q: G = None
        self.w: A = None
        self.y: E = None
        self.txt = txt

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

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

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

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

i = A("i")
e = B("e")
c = C("c")
n = D("n")
a = E("a")
m = F("m")
g = G("g")
k = G("k")

i.s = m
e.t = n
e.v = m
e.r = i
c.x = i
c.w = i
c.s = a
c.y = a
c.z = m
c.q = k
n.t = m
n.v = e
a.r = k
a.u = i
a.s = i
a.w = i
a.p = m
m.z = a
m.r = i
m.y = i
m.s = i
m.u = c
m.v = g
g.v = a
g.x = n
g.u = e
g.y = e
g.r = c
g.s = c
g.o = c
k.v = a
k.x = n
k.u = e
k.y = e
k.r = c
k.s = c
k.o = c
assert a.p.u.z.z.txt == "a"