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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: E = None
        self.o: C = None
        self.z: D = None
        self.q: G = None
        self.r: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: C = None
        self.p: E = None
        self.o: A = None
        self.v: C = None
        self.txt = txt

c = A("c")
i = B("i")
j = C("j")
l = D("l")
e = E("e")
k = F("k")
m = G("m")
a = G("a")
n = C("n")
f = F("f")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: E = None
        self.o: C = None
        self.z: D = None
        self.q: G = None
        self.r: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: C = None
        self.p: E = None
        self.o: A = None
        self.v: C = None
        self.txt = txt

c = A("c")
i = B("i")
j = C("j")
l = D("l")
e = E("e")
k = F("k")
m = G("m")
a = G("a")
n = C("n")
f = F("f")

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