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

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.x: F = None
        self.s: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.q: D = None
        self.p: B = None
        self.t: A = None
        self.x: C = None
        self.w: F = None
        self.o: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.x: F = None
        self.s: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.q: D = None
        self.p: B = None
        self.t: A = None
        self.x: C = None
        self.w: F = None
        self.o: F = None
        self.txt = txt

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

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

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