class A:
    def __init__(self, txt: str):
        self.p: B = None
        self.z: E = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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