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

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

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: D = None
        self.x: E = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: D = None
        self.x: E = None
        self.txt = txt

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

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