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

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: B = None
        self.z: D = None
        self.o: B = None
        self.x: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: E = None
        self.z: B = None
        self.p: E = None
        self.x: F = None
        self.txt = txt

d = A("d")
l = B("l")
k = C("k")
f = D("f")
e = E("e")
i = F("i")
n = A("n")
c = F("c")
g = E("g")
m = A("m")

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

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

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: B = None
        self.z: D = None
        self.o: B = None
        self.x: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.o: E = None
        self.z: B = None
        self.p: E = None
        self.x: F = None
        self.txt = txt

d = A("d")
l = B("l")
k = C("k")
f = D("f")
e = E("e")
i = F("i")
n = A("n")
c = F("c")
g = E("g")
m = A("m")

d.y = g
d.v = l
d.p = e
d.z = m
l.w = f
l.q = k
l.z = m
l.t = m
l.v = e
l.o = e
k.q = e
k.t = l
k.o = l
k.x = l
k.z = f
f.u = l
f.y = k
e.q = m
e.y = n
i.s = l
i.z = l
i.o = g
i.p = g
i.x = c
n.y = e
n.v = l
n.p = g
n.z = d
c.s = l
c.z = l
c.o = e
c.p = e
c.x = i
g.q = m
g.y = m
m.y = e
m.p = e
m.v = l
m.z = n
assert d.p.y.p.y.v.o.y.txt == "n"