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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: A = None
        self.o: C = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.q: A = None
        self.o: A = None
        self.r: D = None
        self.u: C = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: F = None
        self.u: A = None
        self.o: C = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.q: A = None
        self.o: A = None
        self.r: D = None
        self.u: C = None
        self.txt = txt

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

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