class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.r: C = None
        self.u: E = None
        self.t: C = None
        self.s: E = None
        self.p: E = None
        self.z: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: D = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: D = None
        self.t: B = None
        self.p: D = None
        self.z: F = None
        self.q: D = None
        self.x: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: D = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: D = None
        self.t: B = None
        self.p: D = None
        self.z: F = None
        self.q: D = None
        self.x: B = None
        self.txt = txt

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

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