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

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

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: E = None
        self.o: F = None
        self.w: A = None
        self.r: E = None
        self.txt = txt

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

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

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

c = A("c")
f = B("f")
l = C("l")
h = D("h")
e = E("e")
d = F("d")

c.v = e
c.u = e
c.z = e
c.s = h
f.t = h
f.y = l
l.p = e
l.z = e
l.r = e
l.o = d
l.w = c
h.v = f
h.t = f
h.u = e
h.r = e
h.x = e
h.q = c
e.v = d
e.y = l
e.s = l
e.x = h
e.t = h
e.u = f
d.p = c
d.s = c
assert l.o.p.z.v.s.s.txt == "
class A:
    def __init__(self, txt: str):
        self.v: E = None
        self.s: D = None
        self.u: E = None
        self.z: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: E = None
        self.o: F = None
        self.w: A = None
        self.r: E = None
        self.txt = txt

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

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

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

c = A("c")
f = B("f")
l = C("l")
h = D("h")
e = E("e")
d = F("d")

c.v = e
c.u = e
c.z = e
c.s = h
f.t = h
f.y = l
l.p = e
l.z = e
l.r = e
l.o = d
l.w = c
h.v = f
h.t = f
h.u = e
h.r = e
h.x = e
h.q = c
e.v = d
e.y = l
e.s = l
e.x = h
e.t = h
e.u = f
d.p = c
d.s = c
assert l.o.p.z.v.s.s.txt == "h"