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

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

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

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

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

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

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

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

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

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

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

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

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

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

c.v = l
c.x = j
c.p = e
g.q = b
g.w = k
g.o = j
g.y = j
g.p = e
g.z = i
n.w = e
n.q = j
e.z = j
j.o = i
j.r = f
j.x = b
j.z = e
l.q = b
l.p = b
l.r = i
l.o = i
l.u = n
l.s = k
i.q = c
i.p = c
i.r = l
i.o = l
i.u = n
i.s = g
k.q = b
k.w = g
k.o = j
k.y = j
k.p = e
k.z = l
b.v = l
b.x = j
b.p = e
f.w = e
f.q = j
assert c.p.z.r.q.r.w.z.o.u.txt == "n"