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

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.x: C = None
        self.p: D = None
        self.t: F = None
        self.y: B = None
        self.txt = txt

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.x: C = None
        self.p: D = None
        self.t: F = None
        self.y: B = None
        self.txt = txt

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

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

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

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

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

c.u = e
c.y = m
c.s = f
b.z = k
b.y = k
b.x = l
b.p = n
b.t = e
l.r = b
l.o = m
l.p = i
l.v = f
l.u = n
n.o = b
n.v = m
n.t = f
f.r = n
f.o = n
e.v = f
e.q = f
e.x = f
e.o = n
i.u = e
i.y = l
i.s = f
h.v = f
h.q = f
h.x = f
h.o = n
k.z = b
k.y = b
k.x = m
k.p = n
k.t = e
m.r = k
m.o = l
m.p = c
m.v = f
m.u = n
assert m.u.o.y.x.r.p.txt == "n"