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

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

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

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

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

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

j = A("j")
h = B("h")
f = C("f")
a = D("a")
k = E("k")
l = F("l")
c = D("c")
i = F("i")

j.r = i
j.o = k
j.z = k
j.w = c
j.y = h
h.y = a
h.u = f
h.t = f
h.o = i
h.p = k
h.v = k
f.s = h
a.y = h
a.o = k
a.z = f
a.t = f
k.r = j
k.w = f
l.z = i
l.r = k
l.u = k
c.y = h
c.o = k
c.z = f
c.t = f
i.z = l
i.r = k
i.u = k
assert i.u.w.s.v.w.txt == "
class A:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: E = None
        self.w: D = None
        self.y: B = None
        self.z: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

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

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

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

j = A("j")
h = B("h")
f = C("f")
a = D("a")
k = E("k")
l = F("l")
c = D("c")
i = F("i")

j.r = i
j.o = k
j.z = k
j.w = c
j.y = h
h.y = a
h.u = f
h.t = f
h.o = i
h.p = k
h.v = k
f.s = h
a.y = h
a.o = k
a.z = f
a.t = f
k.r = j
k.w = f
l.z = i
l.r = k
l.u = k
c.y = h
c.o = k
c.z = f
c.t = f
i.z = l
i.r = k
i.u = k
assert i.u.w.s.v.w.txt == "f"