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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

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

b = A("b")
n = B("n")
m = C("m")
c = D("c")
l = E("l")
k = F("k")
a = A("a")
e = C("e")
j = E("j")
h = A("h")

b.u = k
b.q = k
b.v = k
b.y = n
b.t = c
b.o = a
n.x = a
n.w = e
n.u = l
n.v = k
n.s = k
m.y = j
m.w = c
m.q = b
m.p = h
m.v = n
c.v = n
l.q = c
k.s = c
k.z = c
k.q = n
k.p = n
k.u = m
k.o = b
a.u = k
a.q = k
a.v = k
a.y = n
a.t = c
a.o = h
e.y = j
e.w = c
e.q = h
e.p = h
e.v = n
j.q = c
h.u = k
h.q = k
h.v = k
h.y = n
h.t = c
h.o = a
assert k.u.v.w.v.u.q.v.u.q.v.txt == "
class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.y: B = None
        self.t: D = None
        self.q: F = None
        self.v: F = None
        self.o: A = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

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

b = A("b")
n = B("n")
m = C("m")
c = D("c")
l = E("l")
k = F("k")
a = A("a")
e = C("e")
j = E("j")
h = A("h")

b.u = k
b.q = k
b.v = k
b.y = n
b.t = c
b.o = a
n.x = a
n.w = e
n.u = l
n.v = k
n.s = k
m.y = j
m.w = c
m.q = b
m.p = h
m.v = n
c.v = n
l.q = c
k.s = c
k.z = c
k.q = n
k.p = n
k.u = m
k.o = b
a.u = k
a.q = k
a.v = k
a.y = n
a.t = c
a.o = h
e.y = j
e.w = c
e.q = h
e.p = h
e.v = n
j.q = c
h.u = k
h.q = k
h.v = k
h.y = n
h.t = c
h.o = a
assert k.u.v.w.v.u.q.v.u.q.v.txt == "n"