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

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

b = A("b")
k = B("k")
c = C("c")
i = D("i")
g = E("g")
l = F("l")
m = D("m")
j = A("j")

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

b = A("b")
k = B("k")
c = C("c")
i = D("i")
g = E("g")
l = F("l")
m = D("m")
j = A("j")

b.q = i
b.z = l
b.p = l
b.o = k
b.v = k
b.r = j
k.o = j
k.z = c
k.u = b
k.t = i
k.p = i
c.w = k
i.u = l
i.s = b
g.o = b
l.r = m
l.w = m
l.u = c
l.v = g
l.p = g
l.y = b
m.u = l
m.s = b
j.q = m
j.z = l
j.p = l
j.o = k
j.v = k
j.r = b
assert l.y.q.s.z.u.w.z.w.txt == "k"