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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.t: A = None
        self.o: B = None
        self.z: F = None
        self.q: A = None
        self.txt = txt

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.t: A = None
        self.o: B = None
        self.z: F = None
        self.q: A = None
        self.txt = txt

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

d.v = m
d.x = k
d.s = k
d.u = k
d.y = l
k.w = i
k.t = l
k.x = j
k.y = e
k.q = d
k.u = m
j.w = l
m.x = l
m.q = l
m.s = l
m.u = i
m.y = k
i.v = j
i.q = k
i.t = k
i.x = m
i.r = m
i.w = e
b.w = e
b.t = e
b.q = e
b.o = k
b.z = h
l.w = j
n.v = m
n.x = k
n.s = k
n.u = k
n.y = j
e.v = m
e.x = k
e.s = k
e.u = k
e.y = l
h.w = e
h.t = e
h.o = k
h.z = b
h.q = d
assert k.u.y.y.y.w.w.txt == "l"