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

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

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

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

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

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

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

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

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

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

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

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

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

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

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